Russia's APT29 Mimics AWS Domains to Steal Windows Credentials

Source: Design Pics Inc via Alamy Stock Photo

Russia’s premiere advanced persistent threat group has been phishing thousands of targets in militaries, public authorities, and enterprises.

APT29 (aka Midnight Blizzard, Nobelium, Cozy Bear) is arguably the world’s most notorious threat actor. An arm of the Russian Federation’s Foreign Intelligence Service (SVR), it’s best known for the historic breaches of SolarWinds and the Democratic National Committee (DNC). Lately, it has breached Microsoft’s codebase and political targets across Europe, Africa, and beyond.

“APT29 embodies the ‘persistent’ part of 'advanced persistent threat,’” says Satnam Narang, senior staff research engineer at Tenable. “It has persistently targeted organizations in the United States and Europe for years, utilizing various techniques, including spear-phishing and exploitation of vulnerabilities to gain initial access and elevate privileges. Its modus operandi is the collection of foreign intelligence, as well as maintaining persistence in compromised organizations in order to conduct future operations.”

Along these same lines, the Computer Emergency Response Team of Ukraine (CERT-UA) recently discovered APT29 phishing Windows credentials from government, military, and private sector targets in Ukraine. And after comparing notes with authorities in other countries, CERT-UA found that the campaign was actually spread across “a wide geography.”

That APT29 would go after sensitive credentials from geopolitically prominent and diverse organizations is no surprise, Narang notes, though he adds that “the one thing that does kind of stray from the path would be its broad targeting, versus [its typical more] narrowly focused attacks.”

AWS and Microsoft

The campaign, which dates back to August, was carried out using malicious domain names designed to seem like they were associated with Amazon Web Services (AWS). The emails sent from these domains pretended to advise recipients on how to integrate AWS with Microsoft services, and how to implement zero trust architecture.

Despite the masquerade, AWS itself reported that the attackers weren’t after Amazon, or its customers’ AWS credentials.

What APT29 really wanted was revealed in the attachments to those emails: configuration files for Remote Desktop, Microsoft’s application for implementing the Remote Desktop Protocol (RDP). RDP is a popular tool that legitimate users and hackers alike use to operate computers remotely.

“Normally, attackers will try to brute force their way into your system or exploit vulnerabilities, then have RDP configured. In this case, they’re basically saying: 'We want to establish that connection [upfront],’” Narang says.

Launching one of these malicious attachments would have immediately triggered an outgoing RDP connection to an APT29 server. But that wasn’t all: The files also contained a number of other malicious parameters, such that when a connection was made, the attacker was given access to the target computer’s storage, clipboard, audio devices, network resources, printers, communication (COM) ports, and more, with the added ability to run custom malicious scripts.

Block RDP

APT29 may not have used any legitimate AWS domains, but Amazon still managed to interrupt the campaign by seizing the group’s malicious copycats.

For potential victims, CERT-UA recommends strict precautions: not just monitoring network logs for connections to IP addresses tied to APT29 but also analyzing all outgoing connections to all IP addresses on the wider Web through the end of the month.

And for organizations at risk in the future, Narang offers simpler advice. “First and foremost, don’t allow RDP files to be received. You can block them at your email gateway. That’s going to kneecap this whole thing,” he says.

AWS declined to provide further comment for this story. Dark Reading has also reached out to Microsoft for its perspective.

About the Author

Nate Nelson is a freelance writer based in New York City. Formerly a reporter at Threatpost, he contributes to a number of cybersecurity blogs and podcasts. He writes “Malicious Life” – an award-winning Top 20 tech podcast on Apple and Spotify – and hosts every other episode, featuring interviews with leading voices in security. He also co-hosts “The Industrial Security Podcast,” the most popular show in its field.