A key malicious domain name used to control potentially thousands of computer systems compromised via the months-long breach at network monitoring software vendor SolarWinds was commandeered by security experts and used as a “killswitch” designed to turn the sprawling cybercrime operation against itself, KrebsOnSecurity has learned.

Austin, Texas-based SolarWinds disclosed this week that a compromise of its software update servers earlier this year may have resulted in malicious code being pushed to nearly 18,000 customers of its Orion platform. Many U.S. federal agencies and Fortune 500 firms use(d) Orion to monitor the health of their IT networks.

On Dec. 13, cyber incident response firm FireEye published a detailed writeup on the malware infrastructure used in the SolarWinds compromise, presenting evidence that the Orion software was first compromised back in March 2020. FireEye said hacked networks were seen communicating with a malicious domain name — avsvmcloud[.]com — one of several domains the attackers had set up to control affected systems.

As first reported here on Tuesday, there were signs over the past few days that control over the domain had been transferred to Microsoft. Asked about the changeover, Microsoft referred questions to FireEye and to GoDaddy, the current domain name registrar for the malicious site.

Today, FireEye responded that the domain seizure was part of a collaborative effort to prevent networks that may have been affected by the compromised SolarWinds software update from communicating with the attackers. What’s more, the company said the domain was reconfigured to act as a “killswitch” that would prevent the malware from continuing to operate in some circumstances.

“SUNBURST is the malware that was distributed through SolarWinds software,” FireEye said in a statement shared with KrebsOnSecurity. “As part of FireEye’s analysis of SUNBURST, we identified a killswitch that would prevent SUNBURST from continuing to operate.”

The statement continues:

“Depending on the IP address returned when the malware resolves avsvmcloud[.]com, under certain conditions, the malware would terminate itself and prevent further execution. FireEye collaborated with GoDaddy and Microsoft to deactivate SUNBURST infections.”

“This killswitch will affect new and previous SUNBURST infections by disabling SUNBURST deployments that are still beaconing to avsvmcloud[.]com. However, in the intrusions FireEye has seen, this actor moved quickly to establish additional persistent mechanisms to access to victim networks beyond the SUNBURST backdoor.

This killswitch will not remove the actor from victim networks where they have established other backdoors. However, it will make it more difficult to for the actor to leverage the previously distributed versions of SUNBURST.”

It is likely that given their visibility into and control over the malicious domain, Microsoft, FireEye, GoDaddy and others now have a decent idea which companies may still be struggling with SUNBURST infections.

The killswitch revelations came as security researchers said they’d made progress in decoding SUNBURST’s obfuscated communications methods. Chinese cybersecurity firm RedDrip Team published their findings on Github, saying its decoder tool had identified nearly a hundred suspected victims of the SolarWinds/Orion breach, including universities, governments and high tech companies.

Meanwhile, the potential legal fallout for SolarWinds in the wake of this breach continues to worsen. The Washington Post reported Tuesday that top investors in SolarWinds sold millions of dollars in stock in the days before the intrusion was revealed. SolarWinds’s stock price has fallen more than 20 percent in the past few days. The Post cited former enforcement officials at the U.S. Securities and Exchange Commission (SEC) saying the sales were likely to prompt an insider trading investigation.

Communications at the U.S. Treasury and Commerce Departments were reportedly compromised by a supply chain attack on SolarWinds, a security vendor that helps the federal government and a range of Fortune 500 companies monitor the health of their IT networks. Given the breadth of the company’s customer base, experts say the incident may be just the first of many such disclosures.

According to a Reuters story, hackers believed to be working for Russia have been monitoring internal email traffic at the U.S. Treasury and Commerce departments. Reuters reports the attackers were able to surreptitiously tamper with updates released by SolarWinds for its Orion platform, a suite of network management tools.

In a security advisory, Austin, Texas based SolarWinds acknowledged its systems “experienced a highly sophisticated, manual supply chain attack on SolarWinds Orion Platform software builds for versions 2019.4 HF 5 through 2020.2.1, released between March 2020 and June 2020.”

In response to the intrusions at Treasury and Commerce, the Department of Homeland Security’s Cybersecurity and Infrastructure Security Agency (CISA) took the unusual step of issuing an emergency directive ordering all federal agencies to immediately disconnect the affected Orion products from their networks.

“Treat all hosts monitored by the SolarWinds Orion monitoring software as compromised by threat actors and assume that further persistence mechanisms have been deployed,” CISA advised.

A blog post by Microsoft says the attackers were able to add malicious code to software updates provided by SolarWinds for Orion users. “This results in the attacker gaining a foothold in the network, which the attacker can use to gain elevated credentials,” Microsoft wrote.

From there, the attackers would be able to forge single sign-on tokens that impersonate any of the organization’s existing users and accounts, including highly privileged accounts on the network.

“Using highly privileged accounts acquired through the technique above or other means, attackers may add their own credentials to existing application service principals, enabling them to call APIs with the permission assigned to that application,” Microsoft explained.

Malicious code added to an Orion software update may have gone undetected by antivirus software and other security tools on host systems thanks in part to guidance from SolarWinds itself. In this support advisory, SolarWinds says its products may not work properly unless their file directories are exempted from antivirus scans and group policy object restrictions.

The Reuters story quotes several anonymous sources saying the intrusions at the Commerce and Treasury departments could be just the tip of the iceberg. That seems like a fair bet.

SolarWinds says it has over 300,000 customers including:

-more than 425 of the U.S. Fortune 500
-all ten of the top ten US telecommunications companies
-all five branches of the U.S. military
-all five of the top five U.S. accounting firms
-the Pentagon
-the State Department
-the National Security Agency
-the Department of Justice
-The White House.

It’s unclear how many of the customers listed on SolarWinds’ website are users of the affected Orion products. But Reuters reports the supply chain attack on SolarWinds is connected to a broad campaign that also involved the recently disclosed hack at FireEye, wherein hackers gained access to a slew of proprietary tools the company uses to help customers find security weaknesses in their computers and networks.

The compromises at the U.S. federal agencies are thought to date back to earlier this summer, and are being blamed on hackers working for the Russian government. FireEye said its breach was the work of APT 29, a.k.a. “Cozy Bear,” a Russian hacker group believed to be associated with one or more intelligence agencies of Russia.

In its own advisory, FireEye said multiple updates poisoned with a malicious backdoor program were digitally signed with a SolarWinds certificate from March through May 2020, and posted to the SolarWindws update website.

FireEye posits the impact of the hack on SolarWinds is widespread, affecting public and private organizations around the world.

“The victims have included government, consulting, technology, telecom and extractive entities in North America, Europe, Asia and the Middle East,” the company’s analysts wrote. “We anticipate there are additional victims in other countries and verticals.”

Microsoft today issued its final batch of security updates for Windows PCs in 2020, ending the year with a relatively light patch load. Nine of the 58 security vulnerabilities addressed this month earned Microsoft’s most-dire “critical” label, meaning they can be abused by malware or miscreants to seize remote control over PCs without any help from users.

Mercifully, it does not appear that any of the flaws fixed this month are being actively exploited, nor have any them been detailed publicly prior to today.

The critical bits reside in updates for Microsoft Exchange Server, Sharepoint Server, and Windows 10 and Server 2016 systems. Additionally, Microsoft released an advisory on how to minimize the risk from a DNS spoofing weakness in Windows Server 2008 through 2019.

Some of the sub-critical “important” flaws addressed this month also probably deserve prompt patching in enterprise environments, including a trio of updates tackling security issues with Microsoft Office.

“Given the speed with which attackers often weaponize Microsoft Office vulnerabilities, these should be prioritized in patching,” said Allan Liska, senior security architect at Recorded Future. “The vulnerabilities, if exploited, would allow an attacker to execute arbitrary code on a victim’s machine. These vulnerabilities affect Microsoft Excel 2013 through 2019, Microsoft 365 32 and 64 bit versions, Microsoft Office 2019 32 and 64 bit versions, and Microsoft Excel for Mac 2019.”

We also learned this week that Redmond quietly addressed a scary “zero-click” vulnerability in its Microsoft Teams platform that would have let anyone execute code of their choosing just by sending the target a specially-crafted chat message to a Teams users. The bug was cross-platform, meaning it could also have been used to deliver malicious code to people using Teams on non-Windows devices.

Researcher Oskars Vegeris said in a proof-of-concept post to Github that he reported the flaw to Microsoft at the end of August, but that Microsoft didn’t assign the bug a Common Vulnerabilities and Exposure (CVE) rating because it has a policy of not doing so for bugs that can be fixed from Microsoft’s end without user interaction.

According to Vegeris, Microsoft addressed the Teams flaw at the end of October. But he said the bug they fixed was the first of five zero or one-click remote code execution flaws he has found and reported in Teams. Reached via LinkedIn, Vegeris declined to say whether Microsoft has yet addressed the remaining Teams issues.

Separately, Adobe issued security updates for its Prelude, Experience Manager and Lightroom software. There were no security updates for Adobe Flash Player, which is fitting considering Adobe is sunsetting the program at the end of the year. Microsoft is taking steps to remove Flash from its Windows browsers, and Google and Firefox already block Flash by default.

It’s a good idea for Windows users to get in the habit of updating at least once a month, but for regular users (read: not enterprises) it’s usually safe to wait a few days until after the patches are released, so that Microsoft has time to iron out any chinks in the new armor.

But before you update, please make sure you have backed up your system and/or important files. It’s not uncommon for a Windows update package to hose one’s system or prevent it from booting properly, and some updates have been 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.

For at least the third time in its existence, OGUsers — a forum overrun with people looking to buy, sell and trade access to compromised social media accounts — has been hacked.

Roughly a week ago, the OGUsers homepage was defaced with a message stating the forum’s user database had been compromised. The hack was acknowledged by the forum’s current administrator, who assured members that their passwords were protected with a password obfuscation technology that was extremely difficult to crack.

But unlike in previous breaches at OGUsers, the perpetrators of this latest incident have not yet released the forum database. In the meantime, someone has been taunting forum members, saying they can have their profiles and private messages removed from an impending database leak by paying between $50 and $100.

OGUsers was hacked at least twice previously, in May 2019 and again in March 2020. In the wake of both incidents, the compromised OGUsers databases were made available for public download.

The leaked databases have been useful in reconstructing who’s behind several high-profile incidents involving compromised social media accounts and virtual currency heists that leveraged SIM swapping, a crime that centers around convincing mobile phone company employees to transfer ownership of the target’s phone number to a device the attackers control.

For example, when several high-profile Twitter accounts were hacked in July 2020 and used to promote bitcoin scams, the profile and private message data from previous OGUser forum compromises proved invaluable in piecing together the “who” behind that scam.

The hacker handles featured in the defacement message left on OGUsers — “Chinese” and “Disco” — correspond to two nicknames used by banned OGUser members who have been trying to generate interest for their own forum that seeks to emulate OGUsers.

Disco, a.k.a “Discoli” a.k.a. “Disco Dog,” is a young man from the United Kingdom who has marketed an automated bot program and service advertised as a way for customers to “cash out” illicit access to OneVanilla Visa prepaid card accounts using PayPal. The same individual also earlier this year founded a corporation in the U.K. called Disco Payments.

Reached via Twitter, Discoli said he and his friends hacked OGUsers via an outdated plugin used by the site. But he claims they have no plans to sell the stolen user data, and said the company was registered as a joke.

“I had a sort of feud with the administrator in the past but this one was more for fun,” Discoli said. “Not too interested in doing damage by releasing database or anything like that.”

As I noted the first time OGUsers got hacked, it’s difficult not to admit feeling a bit of schadenfreude in the continued exposure of a community that has largely specialized in hacking others. Or perhaps in the case of OGUsers, the sentiment may more aptly be described as “schadenfraud.”

Fraudsters redirected email and web traffic destined for several cryptocurrency trading platforms over the past week. The attacks were facilitated by scams targeting employees at GoDaddy, the world’s largest domain name registrar, KrebsOnSecurity has learned.

The incident is the latest incursion at GoDaddy that relied on tricking employees into transferring ownership and/or control over targeted domains to fraudsters. In March, a voice phishing scam targeting GoDaddy support employees allowed attackers to assume control over at least a half-dozen domain names, including transaction brokering site escrow.com.

And in May of this year, GoDaddy disclosed that 28,000 of its customers’ web hosting accounts were compromised following a security incident in Oct. 2019 that wasn’t discovered until April 2020.

This latest campaign appears to have begun on or around Nov. 13, with an attack on cryptocurrency trading platform liquid.com.

“A domain hosting provider ‘GoDaddy’ that manages one of our core domain names incorrectly transferred control of the account and domain to a malicious actor,” Liquid CEO Mike Kayamori said in a blog post. “This gave the actor the ability to change DNS records and in turn, take control of a number of internal email accounts. In due course, the malicious actor was able to partially compromise our infrastructure, and gain access to document storage.”

In the early morning hours of Nov. 18 Central European Time (CET), cyptocurrency mining service NiceHash disccovered that some of the settings for its domain registration records at GoDaddy were changed without authorization, briefly redirecting email and web traffic for the site. NiceHash froze all customer funds for roughly 24 hours until it was able to verify that its domain settings had been changed back to their original settings.

“At this moment in time, it looks like no emails, passwords, or any personal data were accessed, but we do suggest resetting your password and activate 2FA security,” the company wrote in a blog post.

NiceHash founder Matjaz Skorjanc said the unauthorized changes were made from an Internet address at GoDaddy, and that the attackers tried to use their access to its incoming NiceHash emails to perform password resets on various third-party services, including Slack and Github. But he said GoDaddy was impossible to reach at the time because it was undergoing a widespread system outage in which phone and email systems were unresponsive.

“We detected this almost immediately [and] started to mitigate [the] attack,” Skorjanc said in an email to this author. “Luckily, we fought them off well and they did not gain access to any important service. Nothing was stolen.”

Skorjanc said NiceHash’s email service was redirected to privateemail.com, an email platform run by Namecheap Inc., another large domain name registrar. Using Farsight Security, a service which maps changes to domain name records over time, KrebsOnSecurity instructed the service to show all domains registered at GoDaddy that had alterations to their email records in the past week which pointed them to privateemail.com. Those results were then indexed against the top one million most popular websites according to Alexa.com.

The result shows that several other cryptocurrency platforms also may have been targeted by the same group, including Bibox.com, Celsius.network, and Wirex.app. None of these companies responded to requests for comment.

In response to questions from KrebsOnSecurity, GoDaddy acknowledged that “a small number” of customer domain names had been modified after a “limited” number of GoDaddy employees fell for a social engineering scam. GoDaddy said the outage between 7:00 p.m. and 11:00 p.m. PST on Nov. 17 was not related to a security incident, but rather a technical issue that materialized during planned network maintenance.

“Separately, and unrelated to the outage, a routine audit of account activity identified potential unauthorized changes to a small number of customer domains and/or account information,” GoDaddy spokesperson Dan Race said. “Our security team investigated and confirmed threat actor activity, including social engineering of a limited number of GoDaddy employees.”

“We immediately locked down the accounts involved in this incident, reverted any changes that took place to accounts, and assisted affected customers with regaining access to their accounts,” GoDaddy’s statement continued. “As threat actors become increasingly sophisticated and aggressive in their attacks, we are constantly educating employees about new tactics that might be used against them and adopting new security measures to prevent future attacks.”

Race declined to specify how its employees were tricked into making the unauthorized changes, saying the matter was still under investigation. But in the attacks earlier this year that affected escrow.com and several other GoDaddy customer domains, the assailants targeted employees over the phone, and were able to read internal notes that GoDaddy employees had left on customer accounts.

What’s more, the attack on escrow.com redirected the site to an Internet address in Malaysia that hosted fewer than a dozen other domains, including the phishing website servicenow-godaddy.com. This suggests the attackers behind the March incident — and possibly this latest one — succeeded by calling GoDaddy employees and convincing them to use their employee credentials at a fraudulent GoDaddy login page.

In August 2020, KrebsOnSecurity warned about a marked increase in large corporations being targeted in sophisticated voice phishing or “vishing” scams. Experts say the success of these scams has been aided greatly by many employees working remotely thanks to the ongoing Coronavirus pandemic.

A typical vishing scam begins with a series of phone calls to employees working remotely at a targeted organization. The phishers often will explain that they’re calling from the employer’s IT department to help troubleshoot issues with the company’s email or 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.

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.

An alert issued jointly by the FBI and the Cybersecurity and Infrastructure Security Agency (CISA) says the perpetrators of these vishing attacks compile dossiers on employees at their targeted companies using mass scraping of public profiles on social media platforms, recruiter and marketing tools, publicly available background check services, and open-source research.

The FBI/CISA advisory includes a number of suggestions that companies can implement to help mitigate the threat from vishing attacks, including:

• Restrict VPN connections to managed devices only, using mechanisms like hardware checks or installed certificates, so user input alone is not enough to access the corporate VPN.

• Restrict VPN access hours, where applicable, to mitigate access outside of allowed times.

• Employ domain monitoring to track the creation of, or changes to, corporate, brand-name domains.

• Actively scan and monitor web applications for unauthorized access, modification, and anomalous activities.

• Employ the principle of least privilege and implement software restriction policies or other controls; monitor authorized user accesses and usage.

• Consider using a formalized authentication process for employee-to-employee communications made over the public telephone network where a second factor is used to
authenticate the phone call before sensitive information can be discussed.

• Improve 2FA and OTP messaging to reduce confusion about employee authentication attempts.

• Verify web links do not have misspellings or contain the wrong domain.

• Bookmark the correct corporate VPN URL and do not visit alternative URLs on the sole basis of an inbound phone call.

• Be suspicious of unsolicited phone calls, visits, or email messages from unknown individuals claiming to be from a legitimate organization. Do not provide personal information or information about your organization, including its structure or networks, unless you are certain of a person’s authority to have the information. If possible, try to verify the caller’s identity directly with the company.

• If you receive a vishing call, document the phone number of the caller as well as the domain that the actor tried to send you to and relay this information to law enforcement.

• Limit the amount of personal information you post on social networking sites. The internet is a public resource; only post information you are comfortable with anyone seeing.

• Evaluate your settings: sites may change their options periodically, so review your security and privacy settings regularly to make sure that your choices are still appropriate.