Hackers are Selling Tool to Hide Malware in GPUs

Cybercriminals are moving towards malware attacks that can execute code from a hacked system’s graphics processing unit (GPU). Although the approach is not new, and demo code has been published in the past, most of the projects to date have come from academics or were unfinished and unpolished. 

Recently in August, the proof-of-concept (PoC) was sold on a hacker forum, perhaps signaling hackers’ shift to a new level of complexity in their attacks. 

In a brief post on a hacking forum, someone offered to sell the proof-of-concept (PoC) for a strategy that keeps harmful code protected from security solutions scanning the system RAM. The seller gave a brief description of their technique, claiming that it stores malicious code in the GPU memory buffer and then executes it from there. 

As per the advertiser, the project only works on Windows PCs that support OpenCL 2.0 and above for executing code on various processors, including GPUs. It also stated that he tested the code on Intel (UHD 620/630), Radeon (RX 5700), and GeForce (GTX 740M(? ), GTX 1650) graphics cards. 

However, there are fewer details regarding this new hack, but the post went live on August 8 and was apparently sold for an unknown amount on August 25.

Another hacker forum user mentioned that GPU-based malware had been done before, citing JellyFish, a six-year proof-of-concept for a Linux-based GPU rootkit. 

The vendor dismissed the links to the JellyFish malware, stating that their approach is unique and does not rely on code mapping to userspace. There is no information regarding the transaction, such as who purchased it or how much they paid. Only the seller’s article claims to have sold the malware to an unidentified third party. 

Researchers at the VX-Underground threat repository stated in a tweet on Sunday that the malicious code allows binary execution by the GPU in its memory region. They also noted that the technique will be demonstrated soon. 

PoCs for a GPU-based keylogger and a GPU-based remote access trojan for Windows were also disclosed by the same researchers that created the JellyFish rootkit. All three projects were released in May 2015 and are open to the public. 

While the mention of the JellyFish project implies that GPU-based malware is a new idea, the foundation for this attack approach was developed around eight years ago. 

Researchers from the Institute of Computer Science – Foundation for Research and Technology (FORTH) in Greece and Columbia University in New York demonstrated in 2013 that GPUs can execute a keylogger and save recorded keystrokes in their memory space [PDF document here]. 

The researchers previously evidenced that malware authors may use the GPU’s processing capabilities to pack code with extremely sophisticated encryption methods considerably faster than the CPU.