The FBI and NSA have published today a joint security alert containing details about a new strain of Linux malware that the two agencies say was developed and deployed in real-world attacks by Russia’s military hackers.
The two agencies say Russian hackers used the malware, named Drovorub, was to plant backdoors inside hacked networks.
Based on evidence the two agencies have collected, FBI and NSA officials claim the malware is the work of APT28 (Fancy Bear, Sednit), a codename given to the hackers operating out of military unity 26165 of the Russian General Staff Main Intelligence Directorate (GRU) 85th Main SpecialService Center (GTsSS).
Through their joint alert, the two agencies hope to raise awareness in the US private and public sectors so IT administrators can quickly deploy detection rules and prevention measures.
Drovorub — APT28’s swiss-army knife for hacking Linux
Per the two agencies, Drovorub is a multi-component system that comes with an implant, a kernel module rootkit, a file transfer tool, a port-forwarding module, and a command-and-control (C2) server.
“Drovorub is a ‘swiss-army knife’ of capabilities that allows the attacker to perform many different functions, such as stealing files and remote controlling the victim’s computer,” McAfee CTO, Steve Grobman, told ZDNet in an email today.
“In addition to Drovorub’s multiple capabilities, it is designed for stealth by utilizing advanced ‘rootkit’ technologies that make detection difficult,” the McAfee exec added. “The element of stealth allows the operatives to implant the malware in many different types of targets, enabling an attack at any time.”
“The United States is a target-rich environment for potential cyber-attacks. The objectives of Drovorub were not called out in the report, but they could range from industrial espionage to election interference,” Grobman said.
“Technical details released today by the NSA and FBI on APT28’s Drovorub toolset are highly valuable to cyber defenders across the United States.”
To prevent attacks, the agency recommends that US organizations update any Linux system to a version running kernel version 3.7 or later, “in order to take full advantage of kernel signing enforcement,” a security feature that would prevent APT28 hackers from installing Drovorub’s rootkit.
The joint security alert [PDF] contains guidance for running Volatility, probing for file hiding behavior, Snort rules, and Yara rules — all helpful for deploying proper detection measures