VMware Flaw a Vector in SolarWinds Breach?

December 18, 2020
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U.S. government cybersecurity agencies warned this week that the attackers behind the widespread hacking spree stemming from the compromise at network software firm SolarWinds used weaknesses in other, non-SolarWinds products to attack high-value targets. According to sources, among those was a flaw in software virtualization platform VMware, which the U.S. National Security Agency (NSA) warned on Dec. 7 was being used by Russian hackers to impersonate authorized users on victim networks.

On Dec. 7, 2020, the NSA said “Russian state-sponsored malicious cyber actors are exploiting a vulnerability in VMware Access and VMware Identity Manager products, allowing the actors access to protected data and abusing federated authentication.”

VMware released a software update to plug the security hole (CVE-2020-4006) on Dec. 3, and said it learned about the flaw from the NSA.

The NSA advisory (PDF) came less than 24 hours before cyber incident response firm FireEye said it discovered attackers had broken into its networks and stolen more than 300 proprietary software tools the company developed to help customers secure their networks.

On Dec. 13, FireEye disclosed that the incident was the result of the SolarWinds compromise, which involved malicious code being surreptitiously inserted into updates shipped by SolarWinds for users of its Orion network management software as far back as March 2020.

In its advisory on the VMware vulnerability, the NSA urged patching it “as soon as possible,” specifically encouraging the National Security System, Department of Defense, and defense contractors to make doing so a high priority.

The NSA said that in order to exploit this particular flaw, hackers would already need to have access to a vulnerable VMware device’s management interface — i.e., they would need to be on the target’s internal network (provided the vulnerable VMware interface was not accessible from the Internet). However, the SolarWinds compromise would have provided that internal access nicely.

In response to questions from KrebsOnSecurity, VMware said it has “received no notification or indication that the CVE 2020-4006 was used in conjunction with the SolarWinds supply chain compromise.”

VMware added that while some of its own networks used the vulnerable SolarWinds Orion software, an investigation has so far revealed no evidence of exploitation.

“While we have identified limited instances of the vulnerable SolarWinds Orion software in our environment, our own internal investigation has not revealed any indication of exploitation,” the company said in a statement. “This has also been confirmed by SolarWinds own investigations to date.”

On Dec. 17, DHS’s Cybersecurity and Infrastructure Security Agency (CISA) released a sobering alert on the SolarWinds attack, noting that CISA had evidence of additional access vectors other than the SolarWinds Orion platform.

CISA’s advisory specifically noted that “one of the principal ways the adversary is accomplishing this objective is by compromising the Security Assertion Markup Language (SAML) signing certificate using their escalated Active Directory privileges. Once this is accomplished, the adversary creates unauthorized but valid tokens and presents them to services that trust SAML tokens from the environment. These tokens can then be used to access resources in hosted environments, such as email, for data exfiltration via authorized application programming interfaces (APIs).”

Indeed, the NSA’s Dec. 7 advisory said the hacking activity it saw involving the VMware vulnerability “led to the installation of a web shell and follow-on malicious activity where credentials in the form of SAML authentication assertions were generated and sent to Microsoft Active Directory Federation Services (ADFS), which in turn granted the actors access to protected data.”

Also on Dec. 17, the NSA released a far more detailed advisory explaining how it has seen the VMware vulnerability being used to forge SAML tokens, this time specifically referencing the SolarWinds compromise.

Asked about the potential connection, the NSA said only that “if malicious cyber actors gain initial access to networks through the SolarWinds compromise, the TTPs [tactics, techniques and procedures] noted in our December 17 advisory may be used to forge credentials and maintain persistent access.”

“Our guidance in this advisory helps detect and mitigate against this, no matter the initial access method,” the NSA said.

Continue reading →

Malicious Domain in SolarWinds Hack Turned into ‘Killswitch’

December 16, 2020
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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.

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SolarWinds Hack Could Affect 18K Customers

December 15, 2020
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The still-unfolding breach at network management software firm SolarWinds may have resulted in malicious code being pushed to nearly 18,000 customers, the company said in a legal filing on Monday. Meanwhile, Microsoft should soon have some idea which and how many SolarWinds customers were affected, as it recently took possession of a key domain name used by the intruders to control infected systems.

On Dec. 13, SolarWinds acknowledged that hackers had inserted malware into a service that provided software updates for its Orion platform, a suite of products broadly used across the U.S. federal government and Fortune 500 firms to monitor the health of their IT networks.

In a Dec. 14 filing with the U.S. Securities and Exchange Commission (SEC), SolarWinds said roughly 33,000 of its more than 300,000 customers were Orion customers, and that fewer than 18,000 customers may have had an installation of the Orion product that contained the malicious code. SolarWinds said the intrusion also compromised its Microsoft Office 365 accounts.

The initial breach disclosure from SolarWinds came five days after cybersecurity incident response firm FireEye announced it had suffered an intrusion that resulted in the theft of some 300 proprietary software tools the company provides to clients to help secure their IT operations.

On Dec. 13, 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 didn’t explicitly say its own intrusion was the result of the SolarWinds hack, but the company confirmed as much to KrebsOnSecurity earlier today.

Also on Dec. 13, news broke that the SolarWinds hack resulted in attackers reading the email communications at the U.S. Treasury and Commerce departments.

On Dec. 14, Reuters reported the SolarWinds intrusion also had been used to infiltrate computer networks at the U.S. Department of Homeland Security (DHS). That disclosure came less than 24 hours after DHS’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.

ANALYSIS

Security experts have been speculating as to the extent of the damage from the SolarWinds hack, combing through details in the FireEye analysis and elsewhere for clues about how many other organizations may have been hit.

And it seems that Microsoft may now be in perhaps the best position to take stock of the carnage. That’s because sometime on Dec. 14, the software giant took control over a key domain name — avsvmcloud[.]com — that was used by the SolarWinds hackers to communicate with systems compromised by the backdoored Orion product updates.

Armed with that access, Microsoft should be able to tell which organizations have IT systems that are still trying to ping the malicious domain. However, because many Internet service providers and affected companies are already blocking systems from accessing that malicious control domain or have disconnected the vulnerable Orion services, Microsoft’s visibility may be somewhat limited.

Microsoft has a long history of working with federal investigators and the U.S. courts to seize control over domains involved in global malware menaces, particularly when those sites are being used primarily to attack Microsoft Windows customers.

Microsoft dodged direct questions about its visibility into the malware control domain, suggesting those queries would be better put to FireEye or GoDaddy (the current domain registrar for the malware control server). But in a response on Twitter, Microsoft spokesperson Jeff Jones seemed to confirm that control of the malicious domain had changed hands. Continue reading →

U.S. Treasury, Commerce Depts. Hacked Through SolarWinds Compromise

December 14, 2020
183 Comments

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.

Some of SolarWinds’ customers. Source: solarwinds.com

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. Continue reading →

Payment Processing Giant TSYS: Ransomware Incident “Immaterial” to Company

December 10, 2020
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Payment card processing giant TSYS suffered a ransomware attack earlier this month. Since then reams of data stolen from the company have been posted online, with the attackers promising to publish more in the coming days. But the company says the malware did not jeopardize card data, and that the incident was limited to administrative areas of its business.

Headquartered in Columbus, Ga., Total System Services Inc. (TSYS) is the third-largest third-party payment processor for financial institutions in North America, and a major processor in Europe.

TSYS provides payment processing services, merchant services and other payment solutions, including prepaid debit cards and payroll cards. In 2019, TSYS was acquired by financial services firm Global Payments Inc. [NYSE:GPN].

On December 8, the cybercriminal gang responsible for deploying the Conti ransomware strain (also known as “Ryuk“) published more than 10 gigabytes of data that it claimed to have removed from TSYS’s networks.

Conti is one of several cybercriminal groups that maintains a blog which publishes data stolen from victims in a bid to force the negotiation of ransom payments. The gang claims the data published so far represents just 15 percent of the information it offloaded from TSYS before detonating its ransomware inside the company.

In a written response to requests for comment, TSYS said the attack did not affect systems that handle payment card processing.

“We experienced a ransomware attack involving systems that support certain corporate back office functions of a legacy TSYS merchant business,” TSYS said. “We immediately contained the suspicious activity and the business is operating normally.” Continue reading →

Patch Tuesday, Good Riddance 2020 Edition

December 8, 2020
29 Comments

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. Continue reading →

IRS to Make ID Protection PIN Open to All

December 4, 2020
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The U.S. Internal Revenue Service (IRS) said this week that beginning in 2021 it will allow all taxpayers to apply for an identity protection personal identification number (IP PIN), a single-use code designed to block identity thieves from falsely claiming a tax refund in your name. Currently, IP PINs are issued only to those who fill out an ID theft affidavit, or to taxpayers who’ve experienced tax refund fraud in previous years.

Tax refund fraud is a perennial problem involving the use of identity information and often stolen or misdirected W-2 forms to electronically file an unauthorized tax return for the purposes of claiming a refund in the name of a taxpayer.

Victims usually first learn of the crime after having their returns rejected because scammers beat them to it. Even those who are not required to file a return can be victims of refund fraud, as can those who are not actually due a refund from the IRS.  

Many of the reasons why refund fraud remains a problem have to do with timing, and some of them are described in more detail here. But the short answer is the IRS is under tremendous pressure to issue refunds quickly and to minimize “false positives” (flagging legitimate claims as fraud) — even when it may not yet have all of the information needed to accurately distinguish phony filings from legitimate ones. Continue reading →

Account Hijacking Site OGUsers Hacked, Again

December 2, 2020
36 Comments

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.

An offer by the apparent hackers of OGUsers, offering to remove account information from the eventual database leak in exchange for payment.

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. Continue reading →

Bomb Threat, DDoS Purveyor Gets Eight Years

December 1, 2020
26 Comments

A 22-year-old North Carolina man has been sentenced to nearly eight years in prison for conducting bomb threats against thousands of schools in the U.S. and United Kingdom, running a service that launched distributed denial-of-service (DDoS) attacks, and for possessing sexually explicit images of minors.

Timothy Dalton Vaughn from Winston-Salem, N.C. was a key member of the Apophis Squad, a gang of young ne’er-do-wells who made bomb threats to more than 2,400 schools and launched DDoS attacks against countless Web sites — including KrebsOnSecurity on multiple occasions.

The Justice Department says Vaughn and his gang ran a DDoS-for-hire service that they used to shake down victims.

“In early 2018, Vaughn demanded 1.5 bitcoin (then worth approximately $20,000) from a Long Beach company, to prevent denial-of-service attacks on its website,” reads a statement from Nicola Hanna, U.S. attorney for the Central District of California. “When the company refused to pay, he launched a DDoS attack that disabled the company’s website.”

One of many tweets from the attention-starved Apophis Squad, which launched multiple DDoS attacks against KrebsOnSecurity over the past few months.

Dalton, whose online aliases included “WantedbyFeds” and “Hacker_R_US,” pleaded guilty last year to one count of conspiracy to convey threats to injure, convey false information concerning use of explosive device, and intentionally damage a computer; one count of computer hacking; and one count of possession of child pornography.

Federal judge Otis D. Wright II sentenced Vaughn to 95 months for possessing 200 sexually explicit images and videos depicting children, including at least one toddler, the Justice Department said. Vaughn was sentenced to 60 months in federal prison for the remaining charge. The sentences will be served concurrently. Continue reading →

GoDaddy Employees Used in Attacks on Multiple Cryptocurrency Services

November 21, 2020
45 Comments

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. Continue reading →