Tag Archive for: Cyber

Wormable Flaw, 0days Lead Sept. 2022 Patch Tuesday

This month’s Patch Tuesday offers a little something for everyone, including security updates for a zero-day flaw in Microsoft Windows that is under active attack, and another Windows weakness experts say could be used to power a fast-spreading computer worm. Also, Apple has also quashed a pair of zero-day bugs affecting certain macOS and iOS users, and released iOS 16, which offers a new privacy and security feature called “Lockdown Mode.” And Adobe axed 63 vulnerabilities in a range of products.

Microsoft today released software patches to plug at least 64 security holes in Windows and related products. Worst in terms of outright scariness is CVE-2022-37969, which is a “privilege escalation” weakness in the Windows Common Log File System Driver that allows attackers to gain SYSTEM-level privileges on a vulnerable host. Microsoft says this flaw is already being exploited in the wild.

Kevin Breen, director of cyber threat research at Immersive Labs, said any vulnerability that is actively targeted by attackers in the wild must be put to the top of any patching list.

“Not to be fooled by its relatively low CVSS score of 7.8, privilege escalation vulnerabilities are often highly sought after by cyber attackers,” Breen said. “Once an attacker has managed to gain a foothold on a victim’s system, one of their first actions will be to gain a higher level of permissions, allowing the attacker to disable security applications and any device monitoring. There is no known workaround to date, so patching is the only effective mitigation.”

Satnam Narang at Tenable said CVE-2022-24521 — a similar vulnerability in the same Windows log file component — was patched earlier this year as part of Microsoft’s April Patch Tuesday release and was also exploited in the wild.

“CVE-2022-37969 was disclosed by several groups, though it’s unclear if CVE-2022-37969 is a patch-bypass for CVE-2022-24521 at this point,” Narang said.

Another vulnerability Microsoft patched this month — CVE-2022-35803 — also seems to be related to the same Windows log file component. While there are no indications CVE-2022-35803 is being actively exploited, Microsoft suggests that exploitation of this flaw is more likely than not.

Trend Micro’s Dustin Childs called attention to CVE-2022-34718, a remote code execution flaw in the Windows TCP/IP service that could allow an unauthenticated attacker to execute code with elevated privileges on affected systems without user interaction.

“That officially puts it into the ‘wormable’ category and earns it a CVSS rating of 9.8,” Childs said. “However, only systems with IPv6 enabled and IPSec configured are vulnerable. While good news for some, if you’re using IPv6 (as many are), you’re probably running IPSec as well. Definitely test and deploy this update quickly.”

Cisco Talos warns about four critical vulnerabilities fixed this month — CVE-2022-34721 and CVE-2022-34722 — which have severity scores of 9.8, though they are “less likely” to be exploited, according to Microsoft.

“These are remote code execution vulnerabilities in the Windows Internet Key Exchange protocol that could be triggered if an attacker sends a specially crafted IP packet,” wrote Jon Munshaw and Asheer Malhotra. “Two other critical vulnerabilities, CVE-2022-35805 and CVE-2022-34700 exist in on-premises instances of Microsoft Dynamics 365. An authenticated attacker could exploit these vulnerabilities to run a specially crafted trusted solution package and execute arbitrary SQL commands. The attacker could escalate their privileges further and execute commands as the database owner.”

Not to be outdone, Apple fixed at least two zero-day vulnerabilities when it released updates for iOS, iPadOS, macOS and Safari. CVE-2022-32984 is a problem in the deepest recesses of the operating system (the kernel). Apple pushed an emergency update for a related zero-day last month in CVE-2022-32983, which could be used to foist malware on iPhones, iPads and Macs that visited a booby-trapped website.

Also listed under active attack is CVE-2022-32817, which has been fixed on macOS 12.6 (Monterey), macOS 11.7 (Big Sur), iOS 15.7 and iPadOS 15.7, and iOS 16. The same vulnerability was fixed in Apple Watch in July 2022, and credits Xinru Chi of Japanese cybersecurity firm Pangu Lab.

“Interestingly, this CVE is also listed in the advisory for iOS 16, but it is not called out as being under active exploit for that flavor of the OS,” Trend Micro’s Childs noted. “Apple does state in its iOS 16 advisory that ‘Additional CVE entries to be added soon.’ It’s possible other bugs could also impact this version of the OS. Either way, it’s time to update your Apple devices.”

Apple’s iOS 16 includes two new security and privacy features — Lockdown Mode and Safety Check. Wired.com describes Safety Check as a feature for users who are at risk for, or currently experiencing, domestic abuse.

“The tool centralizes a number of controls in one place to make it easier for users to manage and revoke access to their location data and reset privacy-related permissions,” wrote Lily Hay Newman.

“Lockdown Mode, on the other hand, is meant for users who potentially face targeted spyware attacks and aggressive state-backed hacking. The feature comprehensively restricts any nonessential iOS features so there are as few potential points of entry to a device as possible. As more governments and repressive entities around the world have begun purchasing powerful commodity spyware to target individuals of particular importance or interest, iOS’s general security defenses haven’t been able to keep pace with these specialized threats.”

To turn on Lockdown Mode in iOS 16, go to Settings, then Privacy and Security, then Lockdown Mode. Safety Check is located in the same area.

Finally, Adobe released seven patches addressing 63 security holes in Adobe Experience Manager, Bridge, InDesign, Photoshop, InCopy, Animate, and Illustrator. More on those updates is here.

Don’t forget to back up your data and/or system before applying any security updates. If you experience glitches or problems installing any of these patches this month, please consider leaving a comment about it below; there’s a decent chance other readers have experienced the same and may chime in here with useful tips.

Transacting in Person with Strangers from the Internet

Communities like Craigslist, OfferUp, Facebook Marketplace and others are great for finding low- or no-cost stuff that one can pick up directly from a nearby seller, and for getting rid of useful things that don’t deserve to end up in a landfill. But when dealing with strangers from the Internet, there is always a risk that the person you’ve agreed to meet has other intentions.

Nearly all U.S. states now have designated safe trading stations — mostly at local police departments — which ensure that all transactions are handled in plain view of both the authorities and security cameras.

These safe trading places exist because sometimes in-person transactions from the Internet don’t end well for one or more parties involved. The website Craigslistkillers has catalogued news links for at least 132 murders linked to Craigslist transactions since 2015. Many of these killings involved high-priced items like automobiles and consumer electronics, where the prospective buyer apparently intended all along to kill the owner and steal the item offered for sale. Others were motivated simply by a desire to hurt people.

This is not to say that using Craigslist is uniquely risky or dangerous; I’m sure the vast majority of transactions generated by the site end amicably and without physical violence. And that probably holds true for all of Craigslist’s competitors.

Still, the risk of a deal going badly when one meets total strangers from the Internet is not zero, and so it’s only sensible to take a few simple precautions. For example, choosing to transact at a designated safe place such as a police station dramatically reduces the likelihood that anyone wishing you harm would even show up.

I recently stumbled upon one of these designated exchange places by accident, hence my interest in learning more about them. The one I encountered was at a Virginia county sheriff’s office, and it has two parking spots reserved with a sign that reads, “Internet Purchase & Exchange Location: This Area is Under 24 Hour Video Surveillance” [image above].

According to the list maintained at Safetradestations.com, there are four other such designated locations in Northern Virginia. And it appears most states now have them in at least some major cities. Safeexchangepoint.com also has a searchable index of safe trading locations in the United States and Canada.

Granted, not everyone is going to live close to one of these designated trading stations. Or maybe what you want to buy, sell or trade you’d rather not have recorded in front of police cameras. Either way, here are a few tips on staying safe while transacting in real life with strangers from the Internet (compliments of the aforementioned safe trading websites).

The safest exchange points are easily accessible and in a well-lit, public place where transactions are visible to others nearby. Try to arrange a meeting time that is during daylight hours, and consider bringing a friend along — especially when dealing with high-value items like laptops and smart phones.

Safeexchangepoint.com also advises that police or merchants that host their own exchange locations generally won’t get involved in the details of your transaction unless specified otherwise, and that many police departments (but not all) are willing to check the serial number of an item for sale to make sure it’s not known to be stolen property.

Of course, it’s not always practical or possible to haul that old sofa to the local police department, or a used car that isn’t working. In those situations, safetradestations.com has some decent suggestions:

  • Meet at a police station where you can exchange and photocopy each others’ identification papers, such as a driver’s license. Do NOT carry cash to this location.
  • Photocopy the license or identification paper, or use your phone to photograph it.
  • Email the ID information to a friend, or to someone trusted (not to yourself).
  • If you’re selling at home, or going to someone’s home, never be outnumbered. If you’re at home, make sure you have two or three people there — and tell the person who is coming that you will have others with you.
  • At home or an apartment, NEVER let someone go anywhere unaccompanied. Always make sure they are escorted.
  • Never let more than one group come to your home at one time to buy or sell.
  • Beware of common scams, like checks for an amount higher than the amount of the deal; “cashier’s checks” that are forged and presented when the bank is closed.
  • If you are given a cashier’s check, money order or other equivalent, call the bank — at the number listed online, not a number the buyer gives you — to verify the validity of the check.

Violence-as-a-Service: Brickings, Firebombings & Shootings for Hire

A 21-year-old New Jersey man has been arrested and charged with stalking in connection with a federal investigation into groups of cybercriminals who are settling scores by hiring people to carry out physical attacks on their rivals. Prosecutors say the defendant recently participated in several of these schemes — including firing a handgun into a Pennsylvania home and torching a residence in another part of the state with a Molotov Cocktail.

Patrick McGovern-Allen of Egg Harbor Township, N.J. was arrested on Aug. 12 on a warrant from the U.S. Federal Bureau of Investigation. An FBI complaint alleges McGovern-Allen was part of a group of co-conspirators who are at the forefront of a dangerous escalation in coercion and intimidation tactics increasingly used by competing cybercriminal groups.

Prosecutors say that around 2 a.m. on Jan 2, 2022, McGovern-Allen and an unidentified co-conspirator fired multiple handgun rounds into a residence in West Chester, Pa. Fortunately, none of the residents inside the home at the time were injured. But prosecutors say the assailants actually recorded video of the attack as “proof” that the shooting had been carried out.

A copy of that video was obtained by KrebsOnSecurity. According to investigators, McGovern-Allen was one of the shooters, who yelled “Justin Active was here” as they haphazardly fired at least eight rounds into the lower story of the West Chester residence.

On Dec. 18, 2021, police in Abington Township, Pa., responded to reports of a house fire from homeowners who said it sounded like something was thrown at their residence just prior to the fire.

Weeks later, on the day of the shooting in West Chester, a detective with the Westtown East Goshen Police Department contacted the Abington police and shared another video that was circulating on several online message boards that appeared to show two individuals setting fire to the Abington Township residence. The criminal complaint said the two police officers agreed the same suspect was present in both videos.

A copy of that video also was obtained by KrebsOnSecurity, and it shows at least two individuals smashing a window, then lighting a rag-soaked Mad Dog 20/20 grape wine bottle and hurling it at the side of the home [Update: My apologies for the file download link, but YouTube just deleted both of the videos included in this story — for allegedly violating their community standards].

“The Molotov cocktail caused the immediate surrounding area to ignite, including the siding of the house, grass, and the wooden chair,” the government’s complaint against McGovern-Allen states. “The two suspects then fled on foot toward the street and begin yelling something when the video stops.”

The government mentions the victims only by their initials — “K.M.” in the shooting and “A.R.” in the firebombing — but said both had been the target of previous harassment by rival cybercriminal groups that included swatting attacks, wherein the perpetrators spoof a distress call to the police about a hostage situation, suicide or bomb threat with the goal of sending a heavily-armed police response to a targeted address.

A number of previous swatting incidents have turned deadly. But these more “hands-on” and first person attacks are becoming increasingly common within certain cybercriminal communities, particularly those engaged in SIM swapping, a crime in which identity thieves hijack a target’s mobile phone number and use that to wrest control over the victim’s various online accounts and identities.

The complaint mentions a handle and user ID allegedly used by McGovern-Allen’s online persona “Tongue” on the Discord chat service, (user: “Tongue#0001”).

“In the chats, [Tongue] tells other Discord users that he was the person who shot K.M.’s house and that he was willing to commit firebombings using Molotov Cocktails,” the complaint alleges. “For example, in one Discord chat from March 2022, [the defendant] states ‘if you need anything done for $ lmk [“let me know”]/I did a shooting/Molotov/but I can also do things for ur entertainment.”

KrebsOnsecurity reviewed hundreds of chat records tied to this Tongue alias, and it appears both attacks were motivated by a desire to get back at a rival cybercriminal by attacking the female friends of that rival.

Recall that the shooters in the West Chester, Pa. incident shouted “Justin Active was here.” Justin Active is the nickname of an individual who is just as active in the same cybercriminal channels, but who has vehemently denied knowledge of or participation in the shooting. Justin Active said on Telegram that the person targeted in the shooting was his ex-girlfriend, and that the firebombing targeted another friend of his.

Justin Active has claimed for months that McGovern-Allen was responsible for both attacks, saying they were intended as an intimidation tactic against him. “DO THE PATRICK MCGOVERN ALLEN RAID DANCE!,” Justin Active’s alias “Nutcase68” shouted on Telegram on Aug. 12, the same day McGovern-Allen was arrested by authorities.

Justin Active’s version of events seems to be supported by a reference in the criminal complaint to an April 2, 2022 chat in which Tongue explained the reason for the shooting.

“The video/is [K]’s house/getting shit/shot/justin active/ was her current bf/ the reason it happened,” Tongue explained. “So that’s why Justin active was there.”

The Telegram chat channels that Justin Active and Tongue both frequented have hundreds to thousands of members each, and some of the more interesting solicitations on these communities are job offers for in-person assignments and tasks that can be found if one searches for posts titled, “If you live near,” or “IRL job” — short for “in real life” job.

A number of these classified ads are in service of performing “brickings,” where someone is hired to visit a specific address and toss a brick through the target’s window.

“If you live near Edmonton Canada dm me need someone bricked,” reads on Telegram message on May 31, 2022.

“If you live near [address redacted] Lakewood, CA, dm [redacted] Paying 3k to slash the tires,” reads another help wanted ad in the same channel on Feb. 24, 2022. “If you live near here and can brick them, dm [address omitted] Richland, WA,” reads another from that same day.

McGovern-Allen was in the news not long ago. According to a Sept. 2020 story from The Press of Atlantic City, a then 19-year-old Patrick McGovern Allen was injured after driving into a building and forcing residents from their home.

“Police found a 2007 Lexus, driven by Patrick McGovern-Allen, 19, that had lost control and left the road, crashing into the eastern end of the 1600 building,” the story recounted. “The car was driven through the steps that provide access to the second-floor apartments, destroying them, and also caused damage to the outer wall.”

A search on the Inmate Locator of the U.S. Bureau of Prisons website shows that McGovern-Allen remains in federal custody at a detention facility in Philadelphia. He’s currently represented by a public defender who has not responded to requests for comment.

A copy of the criminal complaint against McGovern-Allen is available here (PDF).

ANALYSIS

Many of the individuals involved in paying others to commit these physical attacks are also frequent participants in several Telegram channels focused singularly on SIM swapping activity. As a result, the vast majority of the people being targeted for brickings and other real-life physical assaults tend to be other cybercriminals involved in SIM swapping crimes (or individuals on the periphery of that scene).

There are dozens of SIM swappers who are now teenage or 20-something millionaires, by virtue of having stolen vast sums of cryptocurrencies from SIM swapping victims. And now many of these same individuals are finding that communities like Telegram can be leveraged to hire physical harassment and intimidation of their rivals and competitors.

The primary barrier to hiring someone to brick a home or slash some tires seems to be the costs involved: A number of solicitations for these services advertised payment of $3,000 or more upon proof of successful completion, which usually involves recording the attack and hiring a getaway driver in the town where the crime is to take place (calling a cab or hailing an Uber from the scene of a bricking isn’t the brightest idea).

My fear is these violence-as-a-service offerings will at some point migrate outside of the SIM swapping communities. This is precisely what happened with swatting, which for years was a crime perpetrated almost exclusively against online gamers and people streaming their games online. These days, swatting attacks are commonly used by SIM swapping groups as a way to harass and extort regular Internet users into giving up prized social media account names that can be resold for thousands of dollars.

Final Thoughts on Ubiquiti

Last year, I posted a series of articles about a purported “breach” at Ubiquiti. My sole source for that reporting was the person who has since been indicted by federal prosecutors for his alleged wrongdoing – which includes providing false information to the press.

As a result of the new information that has been provided to me, I no longer have faith in the veracity of my source or the information he provided to me. I always endeavor to ensure that my articles are properly sourced and factual.

This time, I missed the mark and, as a result, I would like to extend my sincerest apologies to Ubiquiti, and I have decided to remove those articles from my website.

How 1-Time Passcodes Became a Corporate Liability

Phishers are enjoying remarkable success using text messages to steal remote access credentials and one-time passcodes from employees at some of the world’s largest technology companies and customer support firms. A recent spate of SMS phishing attacks from one cybercriminal group has spawned a flurry of breach disclosures from affected companies, which are all struggling to combat the same lingering security threat: The ability of scammers to interact directly with employees through their mobile devices.

In mid-June 2022, a flood of SMS phishing messages began targeting employees at commercial staffing firms that provide customer support and outsourcing to thousands of companies. The missives asked users to click a link and log in at a phishing page that mimicked their employer’s Okta authentication page. Those who submitted credentials were then prompted to provide the one-time password needed for multi-factor authentication.

The phishers behind this scheme used newly-registered domains that often included the name of the target company, and sent text messages urging employees to click on links to these domains to view information about a pending change in their work schedule.

The phishing sites leveraged a Telegram instant message bot to forward any submitted credentials in real-time, allowing the attackers to use the phished username, password and one-time code to log in as that employee at the real employer website. But because of the way the bot was configured, it was possible for security researchers to capture the information being sent by victims to the public Telegram server.

This data trove was first reported by security researchers at Singapore-based Group-IB, which dubbed the campaign “0ktapus” for the attackers targeting organizations using identity management tools from Okta.com.

“This case is of interest because despite using low-skill methods it was able to compromise a large number of well-known organizations,” Group-IB wrote. “Furthermore, once the attackers compromised an organization they were quickly able to pivot and launch subsequent supply chain attacks, indicating that the attack was planned carefully in advance.”

It’s not clear how many of these phishing text messages were sent out, but the Telegram bot data reviewed by KrebsOnSecurity shows they generated nearly 10,000 replies over approximately two months of sporadic SMS phishing attacks targeting more than a hundred companies.

A great many responses came from those who were apparently wise to the scheme, as evidenced by the hundreds of hostile replies that included profanity or insults aimed at the phishers: The very first reply recorded in the Telegram bot data came from one such employee, who responded with the username “havefuninjail.”

Still, thousands replied with what appear to be legitimate credentials — many of them including one-time codes needed for multi-factor authentication. On July 20, the attackers turned their sights on internet infrastructure giant Cloudflare.com, and the intercepted credentials show at least three employees fell for the scam.

Image: Cloudflare.com

In a blog post earlier this month, Cloudflare said it detected the account takeovers and that no Cloudflare systems were compromised. Cloudflare said it does not rely on one-time passcodes as a second factor, so there was nothing to provide to the attackers. But Cloudflare said it wanted to call attention to the phishing attacks because they would probably work against most other companies.

“This was a sophisticated attack targeting employees and systems in such a way that we believe most organizations would be likely to be breached,” Cloudflare CEO Matthew Prince wrote. “On July 20, 2022, the Cloudflare Security team received reports of employees receiving legitimate-looking text messages pointing to what appeared to be a Cloudflare Okta login page. The messages began at 2022-07-20 22:50 UTC. Over the course of less than 1 minute, at least 76 employees received text messages on their personal and work phones. Some messages were also sent to the employees family members.”

On three separate occasions, the phishers targeted employees at Twilio.com, a San Francisco based company that provides services for making and receiving text messages and phone calls. It’s unclear how many Twilio employees received the SMS phishes, but the data suggest at least four Twilio employees responded to a spate of SMS phishing attempts on July 27, Aug. 2, and Aug. 7.

On that last date, Twilio disclosed that on Aug. 4 it became aware of unauthorized access to information related to a limited number of Twilio customer accounts through a sophisticated social engineering attack designed to steal employee credentials.

“This broad based attack against our employee base succeeded in fooling some employees into providing their credentials,” Twilio said. “The attackers then used the stolen credentials to gain access to some of our internal systems, where they were able to access certain customer data.”

That “certain customer data” included information on roughly 1,900 users of the secure messaging app Signal, which relied on Twilio to provide phone number verification services. In its disclosure on the incident, Signal said that with their access to Twilio’s internal tools the attackers were able to re-register those users’ phone numbers to another device.

On Aug. 25, food delivery service DoorDash disclosed that a “sophisticated phishing attack” on a third-party vendor allowed attackers to gain access to some of DoorDash’s internal company tools. DoorDash said intruders stole information on a “small percentage” of users that have since been notified. TechCrunch reported last week that the incident was linked to the same phishing campaign that targeted Twilio.

This phishing gang apparently had great success targeting employees of all the major mobile wireless providers, but most especially T-Mobile. Between July 10 and July 16, dozens of T-Mobile employees fell for the phishing messages and provided their remote access credentials.

“Credential theft continues to be an ongoing issue in our industry as wireless providers are constantly battling bad actors that are focused on finding new ways to pursue illegal activities like this,” T-Mobile said in a statement. “Our tools and teams worked as designed to quickly identify and respond to this large-scale smishing attack earlier this year that targeted many companies. We continue to work to prevent these types of attacks and will continue to evolve and improve our approach.”

This same group saw hundreds of responses from employees at some of the largest customer support and staffing firms, including Teleperformanceusa.com, Sitel.com and Sykes.com. Teleperformance did not respond to requests for comment. KrebsOnSecurity did hear from Christopher Knauer, global chief security officer at Sitel Group, the customer support giant that recently acquired Sykes. Knauer said the attacks leveraged newly-registered domains and asked employees to approve upcoming changes to their work schedules.

Image: Group-IB.

Knauer said the attackers set up the phishing domains just minutes in advance of spamming links to those domains in phony SMS alerts to targeted employees. He said such tactics largely sidestep automated alerts generated by companies that monitor brand names for signs of new phishing domains being registered.

“They were using the domains as soon as they became available,” Knauer said. “The alerting services don’t often let you know until 24 hours after a domain has been registered.”

On July 28 and again on Aug. 7, several employees at email delivery firm Mailchimp provided their remote access credentials to this phishing group. According to an Aug. 12 blog post, the attackers used their access to Mailchimp employee accounts to steal data from 214 customers involved in cryptocurrency and finance.

On Aug. 15, the hosting company DigitalOcean published a blog post saying it had severed ties with MailChimp after its Mailchimp account was compromised. DigitalOcean said the MailChimp incident resulted in a “very small number” of DigitalOcean customers experiencing attempted compromises of their accounts through password resets.

According to interviews with multiple companies hit by the group, the attackers are mostly interested in stealing access to cryptocurrency, and to companies that manage communications with people interested in cryptocurrency investing. In an Aug. 3 blog post from email and SMS marketing firm Klaviyo.com, the company’s CEO recounted how the phishers gained access to the company’s internal tools, and used that to download information on 38 crypto-related accounts.

A flow chart of the attacks by the SMS phishing group known as 0ktapus and ScatterSwine. Image: Amitai Cohen for Wiz.io. twitter.com/amitaico.

The ubiquity of mobile phones became a lifeline for many companies trying to manage their remote employees throughout the Coronavirus pandemic. But these same mobile devices are fast becoming a liability for organizations that use them for phishable forms of multi-factor authentication, such as one-time codes generated by a mobile app or delivered via SMS.

Because as we can see from the success of this phishing group, this type of data extraction is now being massively automated, and employee authentication compromises can quickly lead to security and privacy risks for the employer’s partners or for anyone in their supply chain.

Unfortunately, a great many companies still rely on SMS for employee multi-factor authentication. According to a report this year from Okta, 47 percent of workforce customers deploy SMS and voice factors for multi-factor authentication. That’s down from 53 percent that did so in 2018, Okta found.

Some companies (like Knauer’s Sitel) have taken to requiring that all remote access to internal networks be managed through work-issued laptops and/or mobile devices, which are loaded with custom profiles that can’t be accessed through other devices.

Others are moving away from SMS and one-time code apps and toward requiring employees to use physical FIDO multi-factor authentication devices such as security keys, which can neutralize phishing attacks because any stolen credentials can’t be used unless the phishers also have physical access to the user’s security key or mobile device.

This came in handy for Twitter, which announced last year that it was moving all of its employees to using security keys, and/or biometric authentication via their mobile device. The phishers’ Telegram bot reported that on June 16, 2022, five employees at Twitter gave away their work credentials. In response to questions from KrebsOnSecurity, Twitter confirmed several employees were relieved of their employee usernames and passwords, but that its security key requirement prevented the phishers from abusing that information.

Twitter accelerated its plans to improve employee authentication following the July 2020 security incident, wherein several employees were phished and relieved of credentials for Twitter’s internal tools. In that intrusion, the attackers used Twitter’s tools to hijack accounts for some of the world’s most recognizable public figures, executives and celebrities — forcing those accounts to tweet out links to bitcoin scams.

“Security keys can differentiate legitimate sites from malicious ones and block phishing attempts that SMS 2FA or one-time password (OTP) verification codes would not,” Twitter said in an Oct. 2021 post about the change. “To deploy security keys internally at Twitter, we migrated from a variety of phishable 2FA methods to using security keys as our only supported 2FA method on internal systems.”

Update, 6:02 p.m. ET: Clarified that Cloudflare does not rely on TOTP (one-time multi-factor authentication codes) as a second factor for employee authentication.

PayPal Phishing Scam Uses Invoices Sent Via PayPal

Scammers are using invoices sent through PayPal.com to trick recipients into calling a number to dispute a pending charge. The missives — which come from Paypal.com and include a link at Paypal.com that displays an invoice for the supposed transaction — state that the user’s account is about to be charged hundreds of dollars. Recipients who call the supplied toll-free number to contest the transaction are soon asked to download software that lets the scammers assume remote control over their computer.

KrebsOnSecurity recently heard from a reader who received an email from paypal.com that he immediately suspected was phony. The message’s subject read, “Billing Department of PayPal updated your invoice.”

A copy of the phishing message included in the PayPal.com invoice.

While the phishing message attached to the invoice is somewhat awkwardly worded, there are many convincing aspects of this hybrid scam. For starters, all of the links in the email lead to paypal.com. Hovering over the “View and Pay Invoice” button shows the button indeed wants to load a link at paypal.com, and clicking that link indeed brings up an active invoice at paypal.com.

Also, the email headers in the phishing message (PDF) show that it passed all email validation checks as being sent by PayPal, and that it was sent through an Internet address assigned to PayPal.

Both the email and the invoice state that “there is evidence that your PayPal account has been accessed unlawfully.” The message continues:

“$600.00 has been debited to your account for the Walmart Gift Card purchase. This transaction will appear in the automatically deducted amount on PayPal activity after 24 hours. If you suspect you did not make this transaction, immediately contact us at the toll-free number….”

Here’s the invoice that popped up when the “View and Pay Invoice” button was clicked:

The phony PayPal invoice, which was sent and hosted by PayPal.com.

The reader who shared this phishing email said he logged into his PayPal account and could find no signs of the invoice in question. A call to the toll-free number listed in the invoice was received by a man who answered the phone as generic “customer service,” instead of trying to spoof PayPal or Walmart. Very quickly into the conversation he suggested visiting a site called globalquicksupport[.]com to download a remote administration tool. It was clear then where the rest of this call was going.

I can see this scam tricking a great many people, especially since both the email and invoice are sent through PayPal’s systems — which practically guarantees that the message will be successfully delivered. The invoices appear to have been sent from a compromised or fraudulent PayPal Business account, which allows users to send invoices like the one shown above. Details of this scam were shared Wednesday with PayPal’s anti-abuse (phishing@paypal.com) and media relations teams.

PayPal said in a written statement that phishing attempts are common and can take many forms.

“We have a zero-tolerance policy on our platform for attempted fraudulent activity, and our teams work tirelessly to protect our customers,” PayPal said. “We are aware of this well-known phishing scam and have put additional controls in place to mitigate this specific incident. Nonetheless, we encourage customers to always be vigilant online and to contact Customer Service directly if they suspect they are a target of a scam.”

It’s remarkable how well today’s fraudsters have adapted to hijacking the very same tools that financial institutions have long used to make their customers feel safe transacting online. It’s no accident that one of the most prolific scams going right now — the Zelle Fraud Scam — starts with a text message about an unauthorized payment that appears to come from your bank. After all, financial institutions have spent years encouraging customers to sign up for mobile alerts via SMS about suspicious transactions, and to expect the occasional inbound call about possibly fraudulent transactions.

Also, today’s scammers are less interested in stealing your PayPal login than they are in phishing your entire computer and online life with remote administration software, which seems to be the whole point of so many scams these days. Because why rob just one online account when you can plunder them all?

The best advice to sidestep phishing scams is to avoid clicking on links that arrive unbidden in emails, text messages and other mediums. Most phishing scams invoke a temporal element that warns of dire consequences should you fail to respond or act quickly. If you’re unsure whether the message is legitimate, take a deep breath and visit the site or service in question manually — ideally, using a browser bookmark to avoid potential typosquatting sites.

When Efforts to Contain a Data Breach Backfire

Earlier this month, the administrator of the cybercrime forum Breached received a cease-and-desist letter from a cybersecurity firm. The missive alleged that an auction on the site for data stolen from 10 million customers of Mexico’s second-largest bank was fake news and harming the bank’s reputation. The administrator responded to this empty threat by purchasing the stolen banking data and leaking it on the forum for everyone to download.

On August 3, 2022, someone using the alias “Holistic-K1ller” posted on Breached a thread selling data allegedly stolen from Grupo Financiero Banorte, Mexico’s second-biggest financial institution by total loans. Holistic-K1ller said the database included the full names, addresses, phone numbers, Mexican tax IDs (RFC), email addresses and balances on more than 10 million citizens.

There was no reason to believe Holistic-K1ller had fabricated their breach claim. This identity has been highly active on Breached and its predecessor RaidForums for more than two years, mostly selling databases from hacked Mexican entities. Last month, they sold customer information on 36 million customers of the Mexican phone company Telcel; in March, they sold 33,000 images of Mexican IDs — with the front picture and a selfie of each citizen. That same month, they also sold data on 1.4 million customers of Mexican lending platform Yotepresto.

But this history was either overlooked or ignored by Group-IB, the Singapore-based cybersecurity firm apparently hired by Banorte to help respond to the data breach.

“The Group-IB team has discovered a resource containing a fraudulent post offering to buy Grupo Financiero Banorte’s leaked databases,” reads a letter the Breach administrator said they received from Group-IB. “We ask you to remove this post containing Banorte data. Thank you for your cooperation and prompt attention to this urgent matter.”

The administrator of Breached is “Pompompurin,” the same individual who alerted this author in November 2021 to a glaring security hole in a U.S. Justice Department website that was used to spoof security alerts from the FBI. In a post to Breached on Aug. 8, Pompompurin said they bought the Banorte database from Hacker-K1ller’s sales thread because Group-IB was sending emails complaining about it.

“They also attempted to submit DMCA’s against the website,” Pompompurin wrote, referring to legal takedown requests under the Digital Millennium Copyright Act. “Make sure to tell Banorte that now they need to worry about the data being leaked instead of just being sold.”

Banorte did not respond to requests for comment. Nor did Group-IB. But in a brief written statement picked up on Twitter, Banorte said there was no breach involving their infrastructure, and the data being sold is old.

“There has been no violation of our platforms and technological infrastructure,” Banorte said. “The set of information referred to is inaccurate and outdated, and does not put our users and customers at risk.”

That statement may be 100 percent true. Still, it is difficult to think of a better example of how not to do breach response. Banorte shrugging off this incident as a nothingburger is baffling: While it is almost certainly true that the bank balance information in the Banorte leak is now out of date, the rest of the information (tax IDs, phone numbers, email addresses) is harder to change.

“Is there one person from our community that think sending cease and desist letter to a hackers forum operator is a good idea?,” asked Ohad Zaidenberg, founder of CTI League, a volunteer emergency response community that emerged in 2020 to help fight COVID-19 related scams. “Who does it? Instead of helping, they pushed the organization from the hill.”

Kurt Seifried, director of IT for the CloudSecurityAlliance, was similarly perplexed by the response to the Banorte breach.

“If the data wasn’t real….did the bank think a cease and desist would result in the listing being removed?” Seifried wondered on Twitter. “I mean, isn’t selling breach data a worse crime usually than slander or libel? What was their thought process?”

A more typical response when a large bank suspects a breach is to approach the seller privately through an intermediary to ascertain if the information is valid and what it might cost to take it off the market. While it may seem odd to expect cybercriminals to make good on their claims to sell stolen data to only one party, removing sold stolen items from inventory is a fairly basic function of virtually all cybercriminal markets today (apart from perhaps sites that traffic in stolen identity data).

At a minimum, negotiating or simply engaging with a data seller can buy the victim organization additional time and clues with which to investigate the claim and ideally notify affected parties of a breach before the stolen data winds up online.

It is true that a large number of hacked databases put up for sale on the cybercrime underground are sold only after a small subset of in-the-know thieves have harvested all of the low-hanging fruit in the data — e.g., access to cryptocurrency accounts or user credentials that are recycled across multiple websites. And it’s certainly not unheard of for cybercriminals to go back on their word and re-sell or leak information that they have sold previously.

But companies in the throes of responding to a data security incident do themselves and customers no favors when they underestimate their adversaries, or try to intimidate cybercrooks with legal threats. Such responses generally accomplish nothing, except unnecessarily upping the stakes for everyone involved while displaying a dangerous naiveté about how the cybercrime underground works.

Sounding the Alarm on Emergency Alert System Flaws

The Department of Homeland Security (DHS) is urging states and localities to beef up security around proprietary devices that connect to the Emergency Alert System — a national public warning system used to deliver important emergency information, such as severe weather and AMBER alerts. The DHS warning came in advance of a workshop to be held this weekend at the DEFCON security conference in Las Vegas, where a security researcher is slated to demonstrate multiple weaknesses in the nationwide alert system.

A Digital Alert Systems EAS encoder/decoder that Pyle said he acquired off eBay in 2019. It had the username and password for the system printed on the machine.

The DHS warning was prompted by security researcher Ken Pyle, a partner at security firm Cybir. Pyle said he started acquiring old EAS equipment off of eBay in 2019, and that he quickly identified a number of serious security vulnerabilities in a device that is broadly used by states and localities to encode and decode EAS alert signals.

“I found all kinds of problems back then, and reported it to the DHS, FBI and the manufacturer,” Pyle said in an interview with KrebsOnSecurity. “But nothing ever happened. I decided I wasn’t going to tell anyone about it yet because I wanted to give people time to fix it.”

Pyle said he took up the research again in earnest after an angry mob stormed the U.S. Capitol on Jan. 6, 2021.

“I was sitting there thinking, ‘Holy shit, someone could start a civil war with this thing,”’ Pyle recalled. “I went back to see if this was still a problem, and it turns out it’s still a very big problem. So I decided that unless someone actually makes this public and talks about it, clearly nothing is going to be done about it.”

The EAS encoder/decoder devices Pyle acquired were made by Lyndonville, NY-based Digital Alert Systems (formerly Monroe Electronics, Inc.), which issued a security advisory this month saying it released patches in 2019 to fix the flaws reported by Pyle, but that some customers are still running outdated versions of the device’s firmware. That may be because the patches were included in version 4 of the firmware for the EAS devices, and many older models apparently do not support the new software.

“The vulnerabilities identified present a potentially serious risk, and we believe both were addressed in software updates issued beginning Oct 2019,” EAS said in a written statement. “We also provided attribution for the researcher’s responsible disclosure, allowing us to rectify the matters before making any public statements. We are aware that some users have not taken corrective actions and updated their software and should immediately take action to update the latest software version to ensure they are not at risk. Anything lower than version 4.1 should be updated immediately. On July 20, 2022, the researcher referred to other potential issues, and we trust the researcher will provide more detail. We will evaluate and work to issue any necessary mitigations as quickly as possible.”

But Pyle said a great many EAS stakeholders are still ignoring basic advice from the manufacturer, such as changing default passwords and placing the devices behind a firewall, not directly exposing them to the Internet, and restricting access only to trusted hosts and networks.

Pyle, in a selfie that is heavily redacted because the EAS device behind him had its user credentials printed on the lid.

Pyle said the biggest threat to the security of the EAS is that an attacker would only need to compromise a single EAS station to send out alerts locally that can be picked up by other EAS systems and retransmitted across the nation.

“The process for alerts is automated in most cases, hence, obtaining access to a device will allow you to pivot around,” he said. “There’s no centralized control of the EAS because these devices are designed such that someone locally can issue an alert, but there’s no central control over whether I am the one person who can send or whatever. If you are a local operator, you can send out nationwide alerts. That’s how easy it is to do this.”

One of the Digital Alert Systems devices Pyle sourced from an electronics recycler earlier this year was non-functioning, but whoever discarded it neglected to wipe the hard drive embedded in the machine. Pyle soon discovered the device contained the private cryptographic keys and other credentials needed to send alerts through Comcast, the nation’s third-largest cable company.

“I can issue and create my own alert here, which has all the valid checks or whatever for being a real alert station,” Pyle said in an interview earlier this month. “I can create a message that will start propagating through the EAS.”

Comcast told KrebsOnSecurity that “a third-party device used to deliver EAS alerts was lost in transit by a trusted shipping provider between two Comcast locations and subsequently obtained by a cybersecurity researcher.

“We’ve conducted a thorough investigation of this matter and have determined that no customer data, and no sensitive Comcast data, were compromised,” Comcast spokesperson David McGuire said.

The company said it also confirmed that the information included on the device can no longer be used to send false messages to Comcast customers or used to compromise devices within Comcast’s network, including EAS devices.

“We are taking steps to further ensure secure transfer of such devices going forward,” McGuire said. “Separately, we have conducted a thorough audit of all EAS devices on our network and confirmed that they are updated with currently available patches and are therefore not vulnerable to recently reported security issues. We’re grateful for the responsible disclosure and to the security research community for continuing to engage and share information with our teams to make our products and technologies ever more secure. Mr. Pyle informed us promptly of his research and worked with us as we took steps to validate his findings and ensure the security of our systems.”

The user interface for an EAS device.

Unauthorized EAS broadcast alerts have happened enough that there is a chronicle of EAS compromises over at fandom.com. Thankfully, most of these incidents have involved fairly obvious hoaxes.

According to the EAS wiki, in February 2013, hackers broke into the EAS networks in Great Falls, Mt. and Marquette, Mich. to broadcast an alert that zombies had risen from their graves in several counties. In Feb. 2017, an EAS station in Indiana also was hacked, with the intruders playing the same “zombies and dead bodies” audio from the 2013 incidents.

“On February 20 and February 21, 2020, Wave Broadband’s EASyCAP equipment was hacked due to the equipment’s default password not being changed,” the Wiki states. “Four alerts were broadcasted, two of which consisted of a Radiological Hazard Warning and a Required Monthly Test playing parts of the Hip Hop song Hot by artist Young Thug.”

In January 2018, Hawaii sent out an alert to cell phones, televisions and radios, warning everyone in the state that a missile was headed their way. It took 38 minutes for Hawaii to let people know the alert was a misfire, and that a draft alert was inadvertently sent. The news video clip below about the 2018 event in Hawaii does a good job of walking through how the EAS works.

It Might Be Our Data, But It’s Not Our Breach

Image: Shutterstock.

A cybersecurity firm says it has intercepted a large, unique stolen data set containing the names, addresses, email addresses, phone numbers, Social Security Numbers and dates of birth on nearly 23 million Americans. The firm’s analysis of the data suggests it corresponds to current and former customers of AT&T. The telecommunications giant stopped short of saying the data wasn’t theirs, but it maintains the records do not appear to have come from its systems and may be tied to a previous data incident at another company.

Milwaukee-based cybersecurity consultancy Hold Security said it intercepted a 1.6 gigabyte compressed file on a popular dark web file-sharing site. The largest item in the archive is a 3.6 gigabyte file called “dbfull,” and it contains 28.5 million records, including 22.8 million unique email addresses and 23 million unique SSNs. There are no passwords in the database.

Hold Security founder Alex Holden said a number of patterns in the data suggest it relates to AT&T customers. For starters, email addresses ending in “att.net” accounted for 13.7 percent of all addresses in the database, with addresses from SBCGLobal.net and Bellsouth.net — both AT&T companies — making up another seven percent. In contrast, Gmail users made up more than 30 percent of the data set, with Yahoo addresses accounting for 24 percent. More than 10,000 entries in the database list “none@att.com” in the email field.

Hold Security found these email domains account for 87% of all domains in the data set. Nearly 21% belonged to AT&T customers.

Holden’s team also examined the number of email records that included an alias in the username portion of the email, and found 293 email addresses with plus addressing. Of those, 232 included an alias that indicated the customer had signed up at some AT&T property; 190 of the aliased email addresses were “+att@”; 42 were “+uverse@,” an oddly specific reference to a DirecTV/AT&T entity that included broadband Internet. In September 2016, AT&T rebranded U-verse as AT&T Internet.

According to its website, AT&T Internet is offered in 21 states, including Alabama, Arkansas, California, Florida, Georgia, Indiana, Kansas, Kentucky, Louisiana, Michigan, Missouri, Nevada, North Carolina, Ohio, Oklahoma, Tennessee, Texas and Wisconsin. Nearly all of the records in the database that contain a state designation corresponded to those 21 states; all other states made up just 1.64 percent of the records, Hold Security found.

Image: Hold Security.

The vast majority of records in this database belong to consumers, but almost 13,000 of the entries are for corporate entities. Holden said 387 of those corporate names started with “ATT,” with various entries like “ATT PVT XLOW” appearing 81 times. And most of the addresses for these entities are AT&T corporate offices.

How old is this data? One clue may be in the dates of birth exposed in this database. There are very few records in this file with dates of birth after 2000.

“Based on these statistics, we see that the last significant number of subscribers born in March of 2000,” Holden told KrebsOnSecurity, noting that AT&T requires new account holders to be 18 years of age or older. “Therefore, it makes sense that the dataset was likely created close to March of 2018.”

There was also this anomaly: Holden said one of his analysts is an AT&T customer with a 13-letter last name, and that her AT&T bill has always had the same unique misspelling of her surname (they added yet another letter). He said the analyst’s name is identically misspelled in this database.

KrebsOnSecurity shared the large data set with AT&T, as well as Hold Security’s analysis of it. AT&T ultimately declined to say whether all of the people in the database are or were at some point AT&T customers. The company said the data appears to be several years old, and that “it’s not immediately possible to determine the percentage that may be customers.”

“This information does not appear to have come from our systems,” AT&T said in a written statement. “It may be tied to a previous data incident at another company. It is unfortunate that data can continue to surface over several years on the dark web. However, customers often receive notices after such incidents, and advice for ID theft is consistent and can be found online.”

The company declined to elaborate on what they meant by “a previous data incident at another company.”

But it seems likely that this database is related to one that went up for sale on a hacker forum on August 19, 2021. That auction ran with the title “AT&T Database +70M (SSN/DOB),” and was offered by ShinyHunters, a well-known threat actor with a long history of compromising websites and developer repositories to steal credentials or API keys.

Image: BleepingComputer

ShinyHunters established the starting price for the auction at $200,000, but set the “flash” or “buy it now” price at $1 million. The auction also included a small sampling of the stolen information, but that sample is no longer available. The hacker forum where the ShinyHunters sales thread existed was seized by the FBI in April, and its alleged administrator arrested.

But cached copies of the auction, as recorded by cyber intelligence firm Intel 471, show ShinyHunters received bids of up to $230,000 for the entire database before they suspended the sale.

“This thread has been deleted several times,” ShinyHunters wrote in their auction discussion on Sept. 6, 2021. “Therefore, the auction is suspended. AT&T will be available on WHM as soon as they accept new vendors.”

The WHM initialism was a reference to the White House Market, a dark web marketplace that shut down in October 2021.

“In many cases, when a database is not sold, ShinyHunters will release it for free on hacker forums,” wrote BleepingComputer’s Lawrence Abrams, who broke the news of the auction last year and confronted AT&T about the hackers’ claims.

AT&T gave Abrams a similar statement, saying the data didn’t come from their systems.

“When asked whether the data may have come from a third-party partner, AT&T chose not to speculate,” Abrams wrote. “‘Given this information did not come from us, we can’t speculate on where it came from or whether it is valid,’” AT&T told BleepingComputer.

Asked to respond to AT&T’s denial, ShinyHunters told BleepingComputer at the time, “I don’t care if they don’t admit. I’m just selling.”

On June 1, 2022, a 21-year-old Frenchman was arrested in Morocco for allegedly being a member of ShinyHunters. Databreaches.net reports the defendant was arrested on an Interpol “Red Notice” at the request of a U.S. federal prosecutor from Washington state.

Databreaches.net suggests the warrant could be tied to a ShinyHunters theft in May 2020, when the group announced they had exfiltrated 500 GB of Microsoft’s source code from Microsoft’s private GitHub repositories.

“Researchers assess that Shiny Hunters gained access to roughly 1,200 private repositories around March 28, 2020, which have since been secured,” reads a May 2020 alert posted by the New Jersey Cybersecurity & Communications Integration Cell, a component within the New Jersey Office of Homeland Security and Preparedness.

“Though the breach was largely dismissed as insignificant, some images of the directory listing appear to contain source code for Azure, Office, and some Windows runtimes, and concerns have been raised regarding access to private API keys or passwords that may have been mistakenly included in some private repositories,” the alert continues. “Additionally, Shiny Hunters is flooding dark web marketplaces with breached databases.”

Last month, T-Mobile agreed to pay $350 million to settle a consolidated class action lawsuit over a breach in 2021 that affected 40 million current and former customers. The breach came to light on Aug. 16, 2021, when someone starting selling tens of millions of SSN/DOB records from T-Mobile on the same hacker forum where the ShinyHunters would post their auction for the claimed AT&T database just three days later.

T-Mobile has not disclosed many details about the “how” of last year’s breach, but it said the intruder(s) “leveraged their knowledge of technical systems, along with specialized tools and capabilities, to gain access to our testing environments and then used brute force attacks and other methods to make their way into other IT servers that included customer data.”

A sales thread tied to the stolen T-Mobile customer data.

The Security Pros and Cons of Using Email Aliases

One way to tame your email inbox is to get in the habit of using unique email aliases when signing up for new accounts online. Adding a “+” character after the username portion of your email address — followed by a notation specific to the site you’re signing up at — lets you create an infinite number of unique email addresses tied to the same account. Aliases can help users detect breaches and fight spam. But not all websites allow aliases, and they can complicate account recovery. Here’s a look at the pros and cons of adopting a unique alias for each website.

What is an email alias? When you sign up at a site that requires an email address, think of a word or phrase that represents that site for you, and then add that prefaced by a “+” sign just to the left of the “@” sign in your email address. For instance, if I were signing up at example.com, I might give my email address as krebsonsecurity+example@gmail.com. Then, I simply go back to my inbox and create a corresponding folder called “Example,” along with a new filter that sends any email addressed to that alias to the Example folder.

Importantly, you don’t ever use this alias anywhere else. That way, if anyone other than example.com starts sending email to it, it is reasonable to assume that example.com either shared your address with others or that it got hacked and relieved of that information. Indeed, security-minded readers have often alerted KrebsOnSecurity about spam to specific aliases that suggested a breach at some website, and usually they were right, even if the company that got hacked didn’t realize it at the time.

Alex Holden, founder of the Milwaukee-based cybersecurity consultancy Hold Security, said many threat actors will scrub their distribution lists of any aliases because there is a perception that these users are more security- and privacy-focused than normal users, and are thus more likely to report spam to their aliased addresses.

Holden said freshly-hacked databases also are often scrubbed of aliases before being sold in the underground, meaning the hackers will simply remove the aliased portion of the email address.

“I can tell you that certain threat groups have rules on ‘+*@’ email address deletion,” Holden said. “We just got the largest credentials cache ever — 1 billion new credentials to us — and most of that data is altered, with aliases removed. Modifying credential data for some threat groups is normal. They spend time trying to understand the database structure and removing any red flags.”

According to the breach tracking site HaveIBeenPwned.com, only about .03 percent of the breached records in circulation today include an alias.

Email aliases are rare enough that seeing just a few email addresses with the same alias in a breached database can make it trivial to identify which company likely got hacked and leaked said database. That’s because the most common aliases are simply the name of the website where the signup takes place, or some abbreviation or shorthand for it.

Hence, for a given database, if there are more than a handful of email addresses that have the same alias, the chances are good that whatever company or website corresponds to that alias has been hacked.

That might explain the actions of Allekabels, a large Dutch electronics web shop that suffered a data breach in 2021. Allekabels said a former employee had stolen data on 5,000 customers, and that those customers were then informed about the data breach by Allekabels.

But Dutch publication RTL Nieuws said it obtained a copy of the Allekabels user database from a hacker who was selling information on 3.6 million customers at the time, and found that the 5,000 number cited by the retailer corresponded to the number of customers who’d signed up using an alias. In essence, RTL argued, the company had notified only those most likely to notice and complain that their aliased addresses were suddenly receiving spam.

“RTL Nieuws has called more than thirty people from the database to check the leaked data,” the publication explained. “The customers with such a unique email address have all received a message from Allekabels that their data has been leaked – according to Allekabels they all happened to be among the 5000 data that this ex-employee had stolen.”

HaveIBeenPwned’s Hunt arrived at the conclusion that aliases account for about .03 percent of registered email addresses by studying the data leaked in the 2013 breach at Adobe, which affected at least 38 million users. Allekabels’s ratio of aliased users was considerably higher than Adobe’s — .14 percent — but then again European Internet users tend to be more privacy-conscious.

While overall adoption of email aliases is still quite low, that may be changing. Apple customers who use iCloud to sign up for new accounts online automatically are prompted to use Apple’s Hide My Email feature, which creates the account using a unique email address that automatically forwards to a personal inbox.

What are the downsides to using email aliases, apart from the hassle of setting them up? The biggest downer is that many sites won’t let you use a “+” sign in your email address, even though this functionality is clearly spelled out in the email standard.

Also, if you use aliases, it helps to have a reliable mnemonic to remember the alias used for each account (this is a non-issue if you create a new folder or rule for each alias). That’s because knowing the email address for an account is generally a prerequisite for resetting the account’s password, and if you can’t remember the alias you added way back when you signed up, you may have limited options for recovering access to that account if you at some point forget your password.

What about you, Dear Reader? Do you rely on email aliases? If so, have they been useful? Did I neglect to mention any pros or cons? Feel free to sound off in the comments below.