Microsoft today released updates to remedy nearly 130 security vulnerabilities in its Windows operating system and supported software. None of the flaws are known to be currently under active exploitation, but 23 of them could be exploited by malware or malcontents to seize complete control of Windows computers with little or no help from users.

The majority of the most dangerous or “critical” bugs deal with issues in Microsoft’s various Windows operating systems and its web browsers, Internet Explorer and Edge. September marks the seventh month in a row Microsoft has shipped fixes for more than 100 flaws in its products, and the fourth month in a row that it fixed more than 120.

Among the chief concerns for enterprises this month is CVE-2020-16875, which involves a critical flaw in the email software Microsoft Exchange Server 2016 and 2019. An attacker could leverage the Exchange bug to run code of his choosing just by sending a booby-trapped email to a vulnerable Exchange server.

“That doesn’t quite make it wormable, but it’s about the worst-case scenario for Exchange servers,” said Dustin Childs, of Trend Micro’s Zero Day Initiative. “We have seen the previously patched Exchange bug CVE-2020-0688 used in the wild, and that requires authentication. We’ll likely see this one in the wild soon. This should be your top priority.”

Also not great for companies to have around is CVE-2020-1210, which is a remote code execution flaw in supported versions of Microsoft Sharepoint document management software that bad guys could attack by uploading a file to a vulnerable Sharepoint site. Security firm Tenable notes that this bug is reminiscent of CVE-2019-0604, another Sharepoint problem that’s been exploited for cybercriminal gains since April 2019.

Microsoft fixed at least five other serious bugs in Sharepoint versions 2010 through 2019 that also could be used to compromise systems running this software. And because ransomware purveyors have a history of seizing upon Sharepoint flaws to wreak havoc inside enterprises, companies should definitely prioritize deployment of these fixes, says Alan Liska, senior security architect at Recorded Future.

Todd Schell at Ivanti reminds us that Patch Tuesday isn’t just about Windows updates: Google has shipped a critical update for its Chrome browser that resolves at least five security flaws that are rated high severity. If you use Chrome and notice an icon featuring a small upward-facing arrow inside of a circle to the right of the address bar, it’s time to update. Completely closing out Chrome and restarting it should apply the pending updates.

Once again, there are no security updates available today for Adobe’s Flash Player, although the company did ship a non-security software update for the browser plugin. The last time Flash got a security update was June 2020, which may suggest researchers and/or attackers have stopped looking for flaws in it. Adobe says it will retire the plugin at the end of this year, and Microsoft has said it plans to completely remove the program from all Microsoft browsers via Windows Update by then.

Before you update with this month’s patch batch, please make sure you have backed up your system and/or important files. It’s not uncommon for Windows updates to hose one’s system or prevent it from booting properly, and some updates even have known to erase or corrupt files.

So do yourself a favor and backup before installing any patches. Windows 10 even has some built-in tools to help you do that, either on a per-file/folder basis or by making a complete and bootable copy of your hard drive all at once.

And if you wish to ensure Windows has been set to pause updating so you can back up your files and/or system before the operating system decides to reboot and install patches on its own schedule, see this guide.

As always, if you experience glitches or problems installing any of these patches this month, please consider leaving a comment about it below; there’s a better-than-even chance other readers have experienced the same and may chime in here with some helpful tips.

Email service provider Sendgrid is grappling with an unusually large number of customer accounts whose passwords have been cracked, sold to spammers, and abused for sending phishing and email malware attacks. Sendgrid’s parent company Twilio says it is working on a plan to require multi-factor authentication for all of its customers, but that solution may not come fast enough for organizations having trouble dealing with the fallout in the meantime.

Many companies use Sendgrid to communicate with their customers via email, or else pay marketing firms to do that on their behalf using Sendgrid’s systems. Sendgrid takes steps to validate that new customers are legitimate businesses, and that emails sent through its platform carry the proper digital signatures that other companies can use to validate that the messages have been authorized by its customers.

But this also means when a Sendgrid customer account gets hacked and used to send malware or phishing scams, the threat is particularly acute because a large number of organizations allow email from Sendgrid’s systems to sail through their spam-filtering systems.

To make matters worse, links included in emails sent through Sendgrid are obfuscated (mainly for tracking deliverability and other metrics), so it is not immediately clear to recipients where on the Internet they will be taken when they click.

Dealing with compromised customer accounts is a constant challenge for any organization doing business online today, and certainly Sendgrid is not the only email marketing platform dealing with this problem. But according to multiple emails from readers, recent threads on several anti-spam discussion lists, and interviews with people in the anti-spam community, over the past few months there has been a marked increase in malicious, phishous and outright spammy email being blasted out via Sendgrid’s servers.

Rob McEwen is CEO of Invaluement.com, an anti-spam firm whose data on junk email trends are used to improve the spam-blocking technologies deployed by several Fortune 100 companies. McEwen said no other email service provider has come close to generating the volume of spam that’s been emanating from Sendgrid accounts lately.

“As far as the nasty criminal phishes and viruses, I think there’s not even a close second in terms of how bad it’s been with Sendgrid over the past few months,” he said.

Trying to filter out bad emails coming from a major email provider that so many legitimate companies rely upon to reach their customers can be a dicey business. If you filter the emails too aggressively you end up with an unacceptable number of “false positives,” i.e., benign or even desirable emails that get flagged as spam and sent to the junk folder or blocked altogether.

But McEwen said the incidence of malicious spam coming from Sendgrid has gotten so bad that he recently launched a new anti-spam block list specifically to filter out email from Sendgrid accounts that have been known to be blasting large volumes of junk or malicious email.

“Before I implemented this in my own filtering system a week ago, I was getting three to four phone calls or stern emails a week from angry customers wondering why these malicious emails were getting through to their inboxes,” McEwen said. “And I just am not seeing anything this egregious in terms of viruses and spams from the other email service providers.”

In an interview with KrebsOnSecurity, Sendgrid parent firm Twilio acknowledged the company had recently seen an increase in compromised customer accounts being abused for spam. While Sendgrid does allow customers to use multi-factor authentication (also known as two-factor authentication or 2FA), this protection is not mandatory.

But Twilio Chief Security Officer Steve Pugh said the company is working on changes that would require customers to use some form of 2FA in addition to usernames and passwords.

“Twilio believes that requiring 2FA for customer accounts is the right thing to do, and we’re working towards that end,” Pugh said. “2FA has proven to be a powerful tool in securing communications channels. This is part of the reason we acquired Authy and created a line of account security products and services. Twilio, like other platforms, is forming a plan on how to better secure our customers’ accounts through native technologies such as Authy and additional account level controls to mitigate known attack vectors.”

Requiring customers to use some form of 2FA would go a long way toward neutralizing the underground market for compromised Sendgrid accounts, which are sold by a variety of cybercriminals who specialize in gaining access to accounts by targeting users who re-use the same passwords across multiple websites.

One such individual, who goes by the handle “Kromatix” on several forums, is currently selling access to more than 400 compromised Sendgrid user accounts. The pricing attached to each account is based on volume of email it can send in a given month. Accounts that can send up to 40,000 emails a month go for $15, whereas those capable of blasting 10 million missives a month sell for $400.

“I have a large supply of cracked Sendgrid accounts that can be used to generate an API key which you can then plug into your mailer of choice and send massive amounts of emails with ensured delivery,” Kromatix wrote in an Aug. 23 sales thread. “Sendgrid servers maintain a very good reputation with [email service providers] so your content becomes much more likely to get into the inbox so long as your setup is correct.”

Neil Schwartzman, executive director of the anti-spam group CAUCE, said Sendgrid’s 2FA plans are long overdue, noting that the company bought Authy back in 2015.

“Single-factor authentication for a company like this in 2020 is just ludicrous given the potential damage and malicious content we’re seeing,” Schwartzman said.

“I understand that it’s a task to invoke 2FA, and given the volume of customers Sendgrid has that’s something to consider because there’s going to be a lot of customer overhead involved,” he continued. “But it’s not like your bank, social media account, email and plenty of other places online don’t already insist on it.”

Schwartzman said if Twilio doesn’t act quickly enough to fix the problem on its end, the major email providers of the world (think Google, Microsoft and Apple) — and their various machine-learning anti-spam algorithms — may do it for them.

“There is a tipping point after which receiving firms start to lose patience and start to more aggressively filter this stuff,” he said. “If seeing a Sendgrid email according to machine learning becomes a sign of abuse, trust me the machines will make the decisions even if the people don’t.”

At the height of his cybercriminal career, the hacker known as “Hieupc” was earning $125,000 a month running a bustling identity theft service that siphoned consumer dossiers from some of the world’s top data brokers. That is, until his greed and ambition played straight into an elaborate snare set by the U.S. Secret Service. Now, after more than seven years in prison Hieupc is back in his home country and hoping to convince other would-be cybercrooks to use their computer skills for good.

For several years beginning around 2010, a lone teenager in Vietnam named Hieu Minh Ngo ran one of the Internet’s most profitable and popular services for selling “fullz,” stolen identity records that included a consumer’s name, date of birth, Social Security number and email and physical address.

Ngo got his treasure trove of consumer data by hacking and social engineering his way into a string of major data brokers. By the time the Secret Service caught up with him in 2013, he’d made over $3 million selling fullz data to identity thieves and organized crime rings operating throughout the United States.

Matt O’Neill is the Secret Service agent who in February 2013 successfully executed a scheme to lure Ngo out of Vietnam and into Guam, where the young hacker was arrested and sent to the mainland U.S. to face prosecution. O’Neill now heads the agency’s Global Investigative Operations Center, which supports investigations into transnational organized criminal groups.

O’Neill said he opened the investigation into Ngo’s identity theft business after reading about it in a 2011 KrebsOnSecurity story, “How Much is Your Identity Worth?” According to O’Neill, what’s remarkable about Ngo is that to this day his name is virtually unknown among the pantheon of infamous convicted cybercriminals, the majority of whom were busted for trafficking in huge quantities of stolen credit cards.

Ngo’s businesses enabled an entire generation of cybercriminals to commit an estimated $1 billion worth of new account fraud, and to sully the credit histories of countless Americans in the process.

“I don’t know of any other cybercriminal who has caused more material financial harm to more Americans than Ngo,” O’Neill told KrebsOnSecurity. “He was selling the personal information on more than 200 million Americans and allowing anyone to buy it for pennies apiece.”

Freshly released from the U.S. prison system and deported back to Vietnam, Ngo is currently finishing up a mandatory three-week COVID-19 quarantine at a government-run facility. He contacted KrebsOnSecurity from inside this facility with the stated aim of telling his little-known story, and to warn others away from following in his footsteps.

BEGINNINGS

Ten years ago, then 19-year-old hacker Ngo was a regular on the Vietnamese-language computer hacking forums. Ngo says he came from a middle-class family that owned an electronics store, and that his parents bought him a computer when he was around 12 years old. From then on out, he was hooked.

In his late teens, he traveled to New Zealand to study English at a university there. By that time, he was already an administrator of several dark web hacker forums, and between his studies he discovered a vulnerability in the school’s network that exposed payment card data.

“I did contact the IT technician there to fix it, but nobody cared so I hacked the whole system,” Ngo recalled. “Then I used the same vulnerability to hack other websites. I was stealing lots of credit cards.”

Ngo said he decided to use the card data to buy concert and event tickets from Ticketmaster, and then sell the tickets at a New Zealand auction site called TradeMe. The university later learned of the intrusion and Ngo’s role in it, and the Auckland police got involved. Ngo’s travel visa was not renewed after his first semester ended, and in retribution he attacked the university’s site, shutting it down for at least two days.

Ngo said he started taking classes again back in Vietnam, but soon found he was spending most of his time on cybercrime forums.

“I went from hacking for fun to hacking for profits when I saw how easy it was to make money stealing customer databases,” Ngo said. “I was hanging out with some of my friends from the underground forums and we talked about planning a new criminal activity.”

“My friends said doing credit cards and bank information is very dangerous, so I started thinking about selling identities,” Ngo continued. “At first I thought well, it’s just information, maybe it’s not that bad because it’s not related to bank accounts directly. But I was wrong, and the money I started making very fast just blinded me to a lot of things.”

MICROBILT

His first big target was a consumer credit reporting company in New Jersey called MicroBilt.

“I was hacking into their platform and stealing their customer database so I could use their customer logins to access their [consumer] databases,” Ngo said. “I was in their systems for almost a year without them knowing.”

Very soon after gaining access to MicroBilt, Ngo says, he stood up Superget[.]info, a website that advertised the sale of individual consumer records. Ngo said initially his service was quite manual, requiring customers to request specific states or consumers they wanted information on, and he would conduct the lookups by hand.

“I was trying to get more records at once, but the speed of our Internet in Vietnam then was very slow,” Ngo recalled. “I couldn’t download it because the database was so huge. So I just manually search for whoever need identities.”

But Ngo would soon work out how to use more powerful servers in the United States to automate the collection of larger amounts of consumer data from MicroBilt’s systems, and from other data brokers. As I wrote of Ngo’s service back in November 2011:

“Superget lets users search for specific individuals by name, city, and state. Each “credit” costs USD$1, and a successful hit on a Social Security number or date of birth costs 3 credits each. The more credits you buy, the cheaper the searches are per credit: Six credits cost $4.99; 35 credits cost $20.99, and $100.99 buys you 230 credits. Customers with special needs can avail themselves of the “reseller plan,” which promises 1,500 credits for $500.99, and 3,500 credits for $1000.99.

“Our Databases are updated EVERY DAY,” the site’s owner enthuses. “About 99% nearly 100% US people could be found, more than any sites on the internet now.”

Ngo’s intrusion into MicroBilt eventually was detected, and the company kicked him out of their systems. But he says he got back in using another vulnerability.

“I was hacking them and it was back and forth for months,” Ngo said. “They would discover [my accounts] and fix it, and I would discover a new vulnerability and hack them again.”

COURT (AD)VENTURES, AND EXPERIAN

This game of cat and mouse continued until Ngo found a much more reliable and stable source of consumer data: A U.S. based company called Court Ventures, which aggregated public records from court documents. Ngo wasn’t interested in the data collected by Court Ventures, but rather in its data sharing agreement with a third-party data broker called U.S. Info Search, which had access to far more sensitive consumer records.

Using forged documents and more than a few lies, Ngo was able to convince Court Ventures that he was a private investigator based in the United States.

“At first [when] I sign up they asked for some documents to verify,” Ngo said. “So I just used some skill about social engineering and went through the security check.”

Then, in March 2012, something even more remarkable happened: Court Ventures was purchased by Experian, one of the big three major consumer credit bureaus in the United States. And for nine months after the acquisition, Ngo was able to maintain his access.

“After that, the database was under control by Experian,” he said. “I was paying Experian good money, thousands of dollars a month.”

Whether anyone at Experian ever performed due diligence on the accounts grandfathered in from Court Ventures is unclear. But it wouldn’t have taken a rocket surgeon to figure out that this particular customer was up to something fishy.

For one thing, Ngo paid the monthly invoices for his customers’ data requests using wire transfers from a multitude of banks around the world, but mostly from new accounts at financial institutions in China, Malaysia and Singapore.

O’Neill said Ngo’s identity theft website generated tens of thousands of queries each month. For example, the first invoice Court Ventures sent Ngo in December 2010 was for 60,000 queries. By the time Experian acquired the company, Ngo’s service had attracted more than 1,400 regular customers, and was averaging 160,000 monthly queries.

More importantly, Ngo’s profit margins were enormous.

“His service was quite the racket,” he said. “Court Ventures charged him 14 cents per lookup, but he charged his customers about $1 for each query.”

By this time, O’Neill and his fellow Secret Service agents had served dozens of subpoenas tied to Ngo’s identity theft service, including one that granted them access to the email account he used to communicate with customers and administer his site. The agents discovered several emails from Ngo instructing an accomplice to pay Experian using wire transfers from different Asian banks.

TLO

Working with the Secret Service, Experian quickly zeroed in on Ngo’s accounts and shut them down. Aware of an opportunity here, the Secret Service contacted Ngo through an intermediary in the United Kingdom — a known, convicted cybercriminal who agreed to play along. The U.K.-based collaborator told Ngo he had personally shut down Ngo’s access to Experian because he had been there first and Ngo was interfering with his business.

“The U.K. guy told Ngo, ‘Hey, you’re treading on my turf, and I decided to lock you out. But as long as you’re paying a vig through me, your access won’t go away’,” O’Neill recalled.

The U.K. cybercriminal, acting at the behest of the Secret Service and U.K. authorities, told Ngo that if he wanted to maintain his access, he could agree to meet up in person. But Ngo didn’t immediately bite on the offer.

Instead, he weaseled his way into another huge data store. In much the same way he’d gained access to Court Ventures, Ngo got an account at a company called TLO, another data broker that sells access to extremely detailed and sensitive information on most Americans.

TLO’s service is accessible to law enforcement agencies and to a limited number of vetted professionals who can demonstrate they have a lawful reason to access such information. In 2014, TLO was acquired by Trans Union, one of the other three big U.S. consumer credit reporting bureaus.

And for a short time, Ngo used his access to TLO to power a new iteration of his business — an identity theft service rebranded as usearching[.]info. This site also pulled consumer data from a payday loan company that Ngo hacked into, as documented in my Sept. 2012 story, ID Theft Service Tied to Payday Loan Sites. Ngo said the hacked payday loans site gave him instant access to roughly 1,000 new fullz records each day.

BLINDED BY GREED

By this time, Ngo was a multi-millionaire: His various sites and reselling agreements with three Russian-language cybercriminal stores online had earned him more than USD $3 million. He told his parents his money came from helping companies develop websites, and even used some of his ill-gotten gains to pay off the family’s debts (its electronics business had gone belly up, and a family member had borrowed but never paid back a significant sum of money).

But mostly, Ngo said, he spent his money on frivolous things, although he says he’s never touched drugs or alcohol.

“I spent it on vacations and cars and a lot of other stupid stuff,” he said.

When TLO locked Ngo out of his account there, the Secret Service used it as another opportunity for their cybercriminal mouthpiece in the U.K. to turn the screws on Ngo yet again.

“He told Ngo he’d locked him out again, and the he could do this all day long,” O’Neill said. “And if he truly wanted lasting access to all of these places he used to have access to, he would agree to meet and form a more secure partnership.”

After several months of conversing with his apparent U.K.-based tormentor, Ngo agreed to meet him in Guam to finalize the deal. Ngo says he understood at the time that Guam is an unincorporated territory of the United States, but that he discounted the chances that this was all some kind of elaborate law enforcement sting operation.

“I was so desperate to have a stable database, and I got blinded by greed and started acting crazy without thinking,” Ngo said. “Lots of people told me ‘Don’t go!,’ but I told them I have to try and see what’s going on.”

But immediately after stepping off of the plane in Guam, he was apprehended by Secret Service agents.

“One of the names of his identity theft services was findget[.]me,” O’Neill said. “We took that seriously, and we did like he asked.”

This is Part I of a multi-part series. Check back tomorrow (Aug. 27) for Part II, which will examine what investigators learned following Ngo’s arrest, and delve into his more recent effort to right the wrongs he’s done.

The COVID-19 epidemic has brought a wave of email phishing attacks that try to trick work-at-home employees into giving away credentials needed to remotely access their employers’ networks. But one increasingly brazen group of crooks is taking your standard phishing attack to the next level, marketing a voice phishing service that uses a combination of one-on-one phone calls and custom phishing sites to steal VPN credentials from employees.

According to interviews with several sources, this hybrid phishing gang has a remarkably high success rate, and operates primarily through paid requests or “bounties,” where customers seeking access to specific companies or accounts can hire them to target employees working remotely at home.

And over the past six months, the criminals responsible have created dozens if not hundreds of phishing pages targeting some of the world’s biggest corporations. For now at least, they appear to be focusing primarily on companies in the financial, telecommunications and social media industries.

“For a number of reasons, this kind of attack is really effective,” said Allison Nixon, chief research officer at New York-based cyber investigations firm Unit 221B. “Because of the Coronavirus, we have all these major corporations that previously had entire warehouses full of people who are now working remotely. As a result the attack surface has just exploded.”

TARGET: NEW HIRES

A typical engagement begins with a series of phone calls to employees working remotely at a targeted organization. The phishers will explain that they’re calling from the employer’s IT department to help troubleshoot issues with the company’s virtual private networking (VPN) technology.

The goal is to convince the target either to divulge their credentials over the phone or to input them manually at a website set up by the attackers that mimics the organization’s corporate email or VPN portal.

Zack Allen is director of threat intelligence for ZeroFOX, a Baltimore-based company that helps customers detect and respond to risks found on social media and other digital channels. Allen has been working with Nixon and several dozen other researchers from various security firms to monitor the activities of this prolific phishing gang in a bid to disrupt their operations.

Allen said the attackers tend to focus on phishing new hires at targeted companies, and will often pose as new employees themselves working in the company’s IT division. To make that claim more believable, the phishers will create LinkedIn profiles and seek to connect those profiles with other employees from that same organization to support the illusion that the phony profile actually belongs to someone inside the targeted firm.

“They’ll say ‘Hey, I’m new to the company, but you can check me out on LinkedIn’ or Microsoft Teams or Slack, or whatever platform the company uses for internal communications,” Allen said. “There tends to be a lot of pretext in these conversations around the communications and work-from-home applications that companies are using. But eventually, they tell the employee they have to fix their VPN and can they please log into this website.”

SPEAR VISHING

The domains used for these pages often invoke the company’s name, followed or preceded by hyphenated terms such as “vpn,” “ticket,” “employee,” or “portal.” The phishing sites also may include working links to the organization’s other internal online resources to make the scheme seem more believable if a target starts hovering over links on the page.

Allen said a typical voice phishing or “vishing” attack by this group involves at least two perpetrators: One who is social engineering the target over the phone, and another co-conspirator who takes any credentials entered at the phishing page and quickly uses them to log in to the target company’s VPN platform in real-time.

Time is of the essence in these attacks because many companies that rely on VPNs for remote employee access also require employees to supply some type of multi-factor authentication in addition to a username and password — such as a one-time numeric code generated by a mobile app or text message. And in many cases, those codes are only good for a short duration — often measured in seconds or minutes.

But these vishers can easily sidestep that layer of protection, because their phishing pages simply request the one-time code as well.

Allen said it matters little to the attackers if the first few social engineering attempts fail. Most targeted employees are working from home or can be reached on a mobile device. If at first the attackers don’t succeed, they simply try again with a different employee.

And with each passing attempt, the phishers can glean important details from employees about the target’s operations, such as company-specific lingo used to describe its various online assets, or its corporate hierarchy.

Thus, each unsuccessful attempt actually teaches the fraudsters how to refine their social engineering approach with the next mark within the targeted organization, Nixon said.

“These guys are calling companies over and over, trying to learn how the corporation works from the inside,” she said.

NOW YOU SEE IT, NOW YOU DON’T

All of the security researchers interviewed for this story said the phishing gang is pseudonymously registering their domains at just a handful of domain registrars that accept bitcoin, and that the crooks typically create just one domain per registrar account.

“They’ll do this because that way if one domain gets burned or taken down, they won’t lose the rest of their domains,” Allen said.

More importantly, the attackers are careful to do nothing with the phishing domain until they are ready to initiate a vishing call to a potential victim. And when the attack or call is complete, they disable the website tied to the domain.

This is key because many domain registrars will only respond to external requests to take down a phishing website if the site is live at the time of the abuse complaint. This requirement can stymie efforts by companies like ZeroFOX that focus on identifying newly-registered phishing domains before they can be used for fraud.

“They’ll only boot up the website and have it respond at the time of the attack,” Allen said. “And it’s super frustrating because if you file an abuse ticket with the registrar and say, ‘Please take this domain away because we’re 100 percent confident this site is going to be used for badness,’ they won’t do that if they don’t see an active attack going on. They’ll respond that according to their policies, the domain has to be a live phishing site for them to take it down. And these bad actors know that, and they’re exploiting that policy very effectively.”

SCHOOL OF HACKS

Both Nixon and Allen said the object of these phishing attacks seems to be to gain access to as many internal company tools as possible, and to use those tools to seize control over digital assets that can quickly be turned into cash. Primarily, that includes any social media and email accounts, as well as associated financial instruments such as bank accounts and any cryptocurrencies.

Nixon said she and others in her research group believe the people behind these sophisticated vishing campaigns hail from a community of young men who have spent years learning how to social engineer employees at mobile phone companies and social media firms into giving up access to internal company tools.

Traditionally, the goal of these attacks has been gaining control over highly-prized social media accounts, which can sometimes fetch thousands of dollars when resold in the cybercrime underground. But this activity gradually has evolved toward more direct and aggressive monetization of such access.

On July 15, a number of high-profile Twitter accounts were used to tweet out a bitcoin scam that earned more than $100,000 in a few hours. According to Twitter, that attack succeeded because the perpetrators were able to social engineer several Twitter employees over the phone into giving away access to internal Twitter tools.

Nixon said it’s not clear whether any of the people involved in the Twitter compromise are associated with this vishing gang, but she noted that the group showed no signs of slacking off after federal authorities charged several people with taking part in the Twitter hack.

“A lot of people just shut their brains off when they hear the latest big hack wasn’t done by hackers in North Korea or Russia but instead some teenagers in the United States,” Nixon said. “When people hear it’s just teenagers involved, they tend to discount it. But the kinds of people responsible for these voice phishing attacks have now been doing this for several years. And unfortunately, they’ve gotten pretty advanced, and their operational security is much better now.”

PROPER ADULT MONEY-LAUNDERING

While it may seem amateurish or myopic for attackers who gain access to a Fortune 100 company’s internal systems to focus mainly on stealing bitcoin and social media accounts, that access — once established — can be re-used and re-sold to others in a variety of ways.

“These guys do intrusion work for hire, and will accept money for any purpose,” Nixon said. “This stuff can very quickly branch out to other purposes for hacking.”

For example, Allen said he suspects that once inside of a target company’s VPN, the attackers may try to add a new mobile device or phone number to the phished employee’s account as a way to generate additional one-time codes for future access by the phishers themselves or anyone else willing to pay for that access.

Nixon and Allen said the activities of this vishing gang have drawn the attention of U.S. federal authorities, who are growing concerned over indications that those responsible are starting to expand their operations to include criminal organizations overseas.

“What we see now is this group is really good on the intrusion part, and really weak on the cashout part,” Nixon said. “But they are learning how to maximize the gains from their activities. That’s going to require interactions with foreign gangs and learning how to do proper adult money laundering, and we’re already seeing signs that they’re growing up very quickly now.”

WHAT CAN COMPANIES DO?

Many companies now make security awareness and training an integral part of their operations. Some firms even periodically send test phishing messages to their employees to gauge their awareness levels, and then require employees who miss the mark to undergo additional training.

Such precautions, while important and potentially helpful, may do little to combat these phone-based phishing attacks that tend to target new employees. Both Allen and Nixon — as well as others interviewed for this story who asked not to be named — said the weakest link in most corporate VPN security setups these days is the method relied upon for multi-factor authentication.

One multi-factor option — physical security keys — appears to be immune to these sophisticated scams. The most commonly used security keys are inexpensive USB-based devices. A security key implements a form of multi-factor authentication known as Universal 2nd Factor (U2F), which allows the user to complete the login process simply by inserting the USB device and pressing a button on the device. The key works without the need for any special software drivers.

The allure of U2F devices for multi-factor authentication is that even if an employee who has enrolled a security key for authentication tries to log in at an impostor site, the company’s systems simply refuse to request the security key if the user isn’t on their employer’s legitimate website, and the login attempt fails. Thus, the second factor cannot be phished, either over the phone or Internet.

In July 2018, Google disclosed that it had not had any of its 85,000+ employees successfully phished on their work-related accounts since early 2017, when it began requiring all employees to use physical security keys in place of one-time codes.

Probably the most popular maker of security keys is Yubico, which sells a basic U2F Yubikey for $20. It offers regular USB versions as well as those made for devices that require USB-C connections, such as Apple’s newer Mac OS systems. Yubico also sells more expensive keys designed to work with mobile devices. [Full disclosure: Yubico was recently an advertiser on this site].

Nixon said many companies will likely balk at the price tag associated with equipping each employee with a physical security key. But she said as long as most employees continue to work remotely, this is probably a wise investment given the scale and aggressiveness of these voice phishing campaigns.

“The truth is some companies are in a lot of pain right now, and they’re having to put out fires while attackers are setting new fires,” she said. “Fixing this problem is not going to be simple, easy or cheap. And there are risks involved if you somehow screw up a bunch of employees accessing the VPN. But apparently these threat actors really hate Yubikey right now.”

R1 RCM Inc. [NASDAQ:RCM], one of the nation’s largest medical debt collection companies, has been hit in a ransomware attack.

Formerly known as Accretive Health Inc., Chicago-based R1 RCM brought in revenues of $1.18 billion in 2019. The company has more than 19,000 employees and contracts with at least 750 healthcare organizations nationwide.

R1 RCM acknowledged taking down its systems in response to a ransomware attack, but otherwise declined to comment for this story.

The “RCM” portion of its name refers to “revenue cycle management,” an industry which tracks profits throughout the life cycle of each patient, including patient registration, insurance and benefit verification, medical treatment documentation, and bill preparation and collection from patients.

The company has access to a wealth of personal, financial and medical information on tens of millions of patients, including names, dates of birth, Social Security numbers, billing information and medical diagnostic data.

It’s unclear when the intruders first breached R1’s networks, but the ransomware was unleashed more than a week ago, right around the time the company was set to release its 2nd quarter financial results for 2020.

R1 RCM declined to discuss the strain of ransomware it is battling or how it was compromised. Sources close to the investigation tell KrebsOnSecurity the malware is known as Defray.

Defray was first spotted in 2017, and its purveyors have a history of specifically targeting companies in the healthcare space. According to Trend Micro, Defray usually is spread via booby-trapped Microsoft Office documents sent via email.

“The phishing emails the authors use are well-crafted,” Trend Micro wrote. For example, in an attack targeting a hospital, the phishing email was made to look like it came from a hospital IT manager, with the malicious files disguised as patient reports.

Email security company Proofpoint says the Defray ransomware is somewhat unusual in that it is typically deployed in small, targeted attacks as opposed to large-scale “spray and pray” email malware campaigns.

“It appears that Defray may be for the personal use of specific threat actors, making its continued distribution in small, targeted attacks more likely,” Proofpoint observed.

A recent report (PDF) from Corvus Insurance notes that ransomware attacks on companies in the healthcare industry have slowed in recent months, with some malware groups even dubiously pledging they would refrain from targeting these firms during the COVID-19 pandemic. But Corvus says that trend is likely to reverse in the second half of 2020 as the United States moves cautiously toward reopening.

Corvus found that while services that scan and filter incoming email for malicious threats can catch many ransomware lures, an estimated 75 percent of healthcare companies do not use this technology.