A ransomware group called Dark Angels made headlines this past week when it was revealed the crime group recently received a record $75 million data ransom payment from a Fortune 50 company. Security experts say the Dark Angels have been around since 2021, but the group doesn’t get much press because they work alone and maintain a low profile, picking one target at a time and favoring mass data theft over disrupting the victim’s operations.
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Security firm Zscaler ThreatLabz this month ranked Dark Angels as the top ransomware threat for 2024, noting that in early 2024 a victim paid the ransomware group $75 million — higher than any previously recorded ransom payment. ThreatLabz found Dark Angels has conducted some of the largest ransomware attacks to date, and yet little is known about the group.
Brett Stone-Gross, senior director of threat intelligence at ThreatLabz, said Dark Angels operate using an entirely different playbook than most other ransomware groups. For starters, he said, Dark Angels does not employ the typical ransomware affiliate model, which relies on hackers-for-hire to install malicious software that locks up infected systems.
“They really don’t want to be in the headlines or cause business disruptions,” Stone-Gross said. “They’re about making money and attracting as little attention as possible.”
Most ransomware groups maintain flashy victim leak sites which threaten to publish the target’s stolen data unless a ransom demand is paid. But the Dark Angels didn’t even have a victim shaming site until April 2023. And the leak site isn’t particularly well branded; it’s called Dunghill Leak.
The Dark Angels victim shaming site, Dunghill Leak.
“Nothing about them is flashy,” Stone-Gross said. “For the longest time, they didn’t even want to cause a big headline, but they probably felt compelled to create that leaks site because they wanted to show they were serious and that they were going to post victim data and make it accessible.”
Dark Angels is thought to be a Russia-based cybercrime syndicate whose distinguishing characteristic is stealing truly staggering amounts of data from major companies across multiple sectors, including healthcare, finance, government and education. For large businesses, the group has exfiltrated between 10-100 terabytes of data, which can take days or weeks to transfer, ThreatLabz found.
Like most ransom gangs, Dark Angels will publish data stolen from victims who do not pay. Some of the more notable victims listed on Dunghill Leak include the global food distribution firm Sysco, which disclosed a ransomware attack in May 2023; and the travel booking giant Sabre, which was hit by the Dark Angels in September 2023.
Stone-Gross said Dark Angels is often reluctant to deploy ransomware malware because such attacks work by locking up the target’s IT infrastructure, which typically causes the victim’s business to grind to a halt for days, weeks or even months on end. And those types of breaches tend to make headlines quickly.
“They selectively choose whether they want to deploy ransomware or not,” he said. “If they deem they can encrypt some files that won’t cause major disruptions — but will give them a ton of data — that’s what they’ll do. But really, what separates them from the rest is the volume of data they’re stealing. It’s a whole order of magnitude greater with Dark Angels. Companies losing vast amounts of data will pay these high ransoms.”
So who paid the record $75 million ransom? Bleeping Computer posited on July 30 that the victim was the pharmaceutical giant Cencora (formerly AmeriSourceBergen Corporation), which reported a data security incident to the U.S. Securities and Exchange Commission (SEC) on February 21, 2024.
The SEC requires publicly-traded companies to disclose a potentially material cybersecurity event within four days of the incident. Cencora is currently #10 on the Fortune 500 list, generating more than $262 billion in revenue last year.
Cencora did not respond to questions about whether it had made a ransom payment in connection with the February cybersecurity incident, and referred KrebsOnSecurity to expenses listed under “Other” in the restructuring section of their latest quarterly financial report (PDF). That report states that the majority of the $30 million cost in “Other” was associated with the breach.
Cencora’s quarterly statement said the incident affected a standalone legacy information technology platform in one country and the foreign business unit’s ability to operate in that country for approximately two weeks.
Cencora’s 2024 1st quarter report documents a $30 million cost associated with a data exfiltration event in mid-February 2024.
In its most recent State of Ransomware report (PDF), security firm Sophos found the average ransomware payment had increased fivefold in the past year, from $400,000 in 2023 to $2 million. Sophos says that in more than four-fifths (82%) of cases funding for the ransom came from multiple sources. Overall, 40% of total ransom funding came from the organizations themselves and 23% from insurance providers.
Further reading: ThreatLabz ransomware report (PDF).
Microsoft Corp. today released software updates to quash 130 security bugs in its Windows operating systems and related software, including at least five flaws that are already seeing active exploitation. Meanwhile, Apple customers have their own zero-day woes again this month: On Monday, Apple issued (and then quickly pulled) an emergency update to fix a zero-day vulnerability that is being exploited on MacOS and iOS devices.
On July 10, Apple pushed a “Rapid Security Response” update to fix a code execution flaw in the Webkit browser component built into iOS, iPadOS, and macOS Ventura. Almost as soon as the patch went out, Apple pulled the software because it was reportedly causing problems loading certain websites. MacRumors says Apple will likely re-release the patches when the glitches have been addressed.
Launched in May, Apple’s Rapid Security Response updates are designed to address time-sensitive vulnerabilities, and this is the second month Apple has used it. July marks the sixth month this year that Apple has released updates for zero-day vulnerabilities — those that get exploited by malware or malcontents before there is an official patch available.
If you rely on Apple devices and don’t have automatic updates enabled, please take a moment to check the patch status of your various iDevices. The latest security update that includes the fix for the zero-day bug should be available in iOS/iPadOS 16.5.1, macOS 13.4.1, and Safari 16.5.2.
On the Windows side, there are at least four vulnerabilities patched this month that earned high CVSS (badness) scores and that are already being exploited in active attacks, according to Microsoft. They include CVE-2023-32049, which is a hole in Windows SmartScreen that lets malware bypass security warning prompts; and CVE-2023-35311 allows attackers to bypass security features in Microsoft Outlook.
The two other zero-day threats this month for Windows are both privilege escalation flaws. CVE-2023-32046 affects a core Windows component called MSHTML, which is used by Windows and other applications, like Office, Outlook and Skype. CVE-2023-36874 is an elevation of privilege bug in the Windows Error Reporting Service.
Many security experts expected Microsoft to address a fifth zero-day flaw — CVE-2023-36884 — a remote code execution weakness in Office and Windows.
“Surprisingly, there is no patch yet for one of the five zero-day vulnerabilities,” said Adam Barnett, lead software engineer at Rapid7. “Microsoft is actively investigating publicly disclosed vulnerability, and promises to update the advisory as soon as further guidance is available.”
Barnett notes that Microsoft links exploitation of this vulnerability with Storm-0978, the software giant’s name for a cybercriminal group based out of Russia that is identified by the broader security community as RomCom.
“Exploitation of CVE-2023-36884 may lead to installation of the eponymous RomCom trojan or other malware,” Barnett said. “[Microsoft] suggests that RomCom / Storm-0978 is operating in support of Russian intelligence operations. The same threat actor has also been associated with ransomware attacks targeting a wide array of victims.”
Microsoft’s advisory on CVE-2023-36884 is pretty sparse, but it does include a Windows registry hack that should help mitigate attacks on this vulnerability. Microsoft has also published a blog post about phishing campaigns tied to Storm-0978 and to the exploitation of this flaw.
Barnett said it’s while it’s possible that a patch will be issued as part of next month’s Patch Tuesday, Microsoft Office is deployed just about everywhere, and this threat actor is making waves.
“Admins should be ready for an out-of-cycle security update for CVE-2023-36884,” he said.
Microsoft also today released new details about how it plans to address the existential threat of malware that is cryptographically signed by…wait for it….Microsoft.
In late 2022, security experts at Sophos, Trend Micro and Cisco warned that ransomware criminals were using signed, malicious drivers in an attempt to evade antivirus and endpoint detection and response (EDR) tools.
In a blog post today, Sophos’s Andrew Brandt wrote that Sophos identified 133 malicious Windows driver files that were digitally signed since April 2021, and found 100 of those were actually signed by Microsoft. Microsoft said today it is taking steps to ensure those malicious driver files can no longer run on Windows computers.
As KrebsOnSecurity noted in last month’s story on malware signing-as-a-service, code-signing certificates are supposed to help authenticate the identity of software publishers, and provide cryptographic assurance that a signed piece of software has not been altered or tampered with. Both of these qualities make stolen or ill-gotten code-signing certificates attractive to cybercriminal groups, who prize their ability to add stealth and longevity to malicious software.
Dan Goodin at Ars Technica contends that whatever Microsoft may be doing to keep maliciously signed drivers from running on Windows is being bypassed by hackers using open source software that is popular with video game cheaters.
“The software comes in the form of two software tools that are available on GitHub,” Goodin explained. “Cheaters use them to digitally sign malicious system drivers so they can modify video games in ways that give the player an unfair advantage. The drivers clear the considerable hurdle required for the cheat code to run inside the Windows kernel, the fortified layer of the operating system reserved for the most critical and sensitive functions.”
Meanwhile, researchers at Cisco’s Talos security team found multiple Chinese-speaking threat groups have repurposed the tools—one apparently called “HookSignTool” and the other “FuckCertVerifyTimeValidity.”
“Instead of using the kernel access for cheating, the threat actors use it to give their malware capabilities it wouldn’t otherwise have,” Goodin said.
For a closer look at the patches released by Microsoft today, check out the always-thorough Patch Tuesday roundup from the SANS Internet Storm Center. And it’s not a bad idea to hold off updating for a few days until Microsoft works out any kinks in the updates: AskWoody.com usually has the lowdown on any patches that may be causing problems for Windows users.
And as ever, please consider backing up your system or at least your important documents and data before applying system updates. If you encounter any problems with these updates, please drop a note about it here in the comments.