Security researchers believe cybercriminals may be taking a page from government agencies when it comes to malware.
According to Sentinel Labs, that metaphorical page has the name of a piece of malware known as ‘Gyges’ scribbled on it, as well as a list of capabilities normally associated with malware linked to cyber-espionage. The malware appears to originate from Russia, and is believed to have been designed to target government organizations.
The specific variant of Gyges observed by Sentinel Labs contained what the firm’s researchers called sophisticated anti-tampering and anti-detection techniques. It also waited for user inactivity – as opposed waiting for user activity, like most malware – in order to bypass sandbox-based security products that emulate users to trigger malware execution.
The malicious code used by the malware for its evasion techniques is significantly more complex than the core executable, the researchers noted in a report on the malware. This led them to believe it was previously used as a “bus” or “carrier” for more sophisticated attacks. After some digging, they found traces inside the “carrier” code connected to previous targeted attacks that had the same characteristics.
“The carrier code we detected in the wild uses evasion techniques that make it invisible to virtually all security mechanisms,” said Udi Shamir, head of research at Sentinel Labs. “This level of sophistication is only typically seen in government-grade malware used for espionage. When we cross referenced this code with our intelligence database it demonstrated similarities to earlier nation state attack code that points back to Russia. This code is too complex and costly to develop for cyber-crime applications. We believe it was developed for cyber espionage, was modularized for use with commodity malware like ransomware and financial Trojans, and was leaked to cyber criminals.”
According to the firm, the code has been repurposed most often for ransomware attacks like Cryptolocker, as well as online banking fraud. The malware has been seen spreading through drive-by downloads and phishing schemes.
The malware targets Windows 7 and 8 platforms and is designed for both x86 and x64 CPU architectures. It is also packed with a heavily-modified Yoda’s Protector, which provides polymorphic encryption and anti-debugging, the security firm notes in a report on the malware. Among its capabilities, the malware counts data exfiltration, screen capture and keylogging.
But perhaps the most interesting element of Gyges is its use of lesser known injection techniques.
“For example, Gyges uses a hooking bypass technique that exploits a logic bug in Windows 7 and Windows 8 (x86 and x64 versions),” Shamir explained. “The hooking bypass trick is simple. The malware translates its operations from 32bit to Native 64bit code, hiding the malicious activity. Each translation from 32bit to 64bit will not be detected by hooking what is injected to the Windows-on-Windows subsystem.”
Sentinel Labs CEO Tomer Weingarten told SecurityWeek that a big concern is that the code can be “bolted-on” to commodity malware like ransomware and online banking Trojans, making them difficult to detect by security tools.
More on the malware can be read here.
