Cybercriminals Hijacking Vulnerable SSH Servers in New Proxyjacking Campaign

Cybercriminals Hijacking Vulnerable SSH Servers in New Proxyjacking Campaign

An active financially motivated campaign is targeting vulnerable SSH servers to covertly ensnare them into a proxy network.

“This is an active campaign in which the attacker leverages SSH for remote access, running malicious scripts that stealthily enlist victim servers into a peer-to-peer (P2P) proxy network, such as Peer2Profit or Honeygain,” Akamai researcher Allen West said in a Thursday report.

Unlike cryptojacking, in which a compromised system’s resources are used to illicitly mine cryptocurrency, proxyjacking offers the ability for threat actors to leverage the victim’s unused bandwidth to clandestinely run different services as a P2P node.

“It is a stealthier alternative to cryptojacking and has serious implications that can increase the headaches that proxied Layer 7 attacks already serve,” West said.

To make matters worse, the anonymity provided by proxyware services can be a double-edged sword in that they could be abused by malicious actors to obfuscate the source of their attacks by routing traffic through intermediary nodes.

Proxyjacking Campaign

Akamai, which discovered the latest campaign on June 8, 2023, said the activity is designed to breach susceptible SSH servers and deploy an obfuscated Bash script that, in turn, is equipped to fetch necessary dependencies from a compromised web server, including the curl command-line tool by camouflaging it as a CSS file (“csdark.css”).

While proxyware is not inherently nefarious, Akamai noted that “some of these companies do not properly verify the sourcing of the IPs in the network, and even occasionally suggest that people install the software on their work computers.”

But such operations can also transcend into the realm of cybercrime when the applications are installed without the users’ knowledge or consent, thereby allowing the threat actor to control several systems and generate illegitimate revenue.