Hackers are dropping standard malware such as Zeus, in favour of more advanced but harder-to-use remote access Trojans (RATs) such as Xtreme RAT, according to security firm FireEye.
Senior researcher at FireEye Nart Villeneuve reported uncovering the trend in a blog post. "During our investigation we found that the majority of Xtreme RAT activity is associated with spam campaigns that typically distribute Zeus variants and other banking-focused malware," he said. "This seems odd, considering RATs require manual labour as opposed to automated banking Trojans."
Xtreme RAT is a notorious RAT that has been freely available on a number of cyber black markets since June 2010. The RAT is dangerous as it can be used for a variety of purposes, including interacting with the victim machine via a remote shell, uploading and downloading files, interacting with the registry and manipulating running processes and services.
There have also been recorded variants able to force infected machines to capture images of the desktop, and record from connected devices, such as webcams and microphones. Hackers can also customise Xtreme RAT to add new abilities, as its source code has been leaked online.
Villeneuve told V3 the attacks have in general been fairly basic spam-related attacks and is yet to see criminals use its increased powers for more advanced purposes.
"Xtreme RAT is now being used in some high-volume attacks. It is being distributed as a payload of traditional large-volume spam runs," he said. "So far, Xtreme RAT has not been used as the payload of advanced exploits. Rather users are lured into installing the RAT through a variety of social engineering schemes."
The attacks have reportedly hit numerous industries. Villeneuve explained: "Using telemetry from FireEye's Dynamic Threat Intelligence (DTI) cloud, we examined 165 Xtreme RAT samples from attacks that primarily hit the energy, utilities, petroleum refining, financial services and high-tech sectors."
He added that FireEye did uncover evidence linking four of the 165 examples to the notorious MoleRats campaign. The original MoleRats campaign began in 2012 and saw hackers target a number of government groups in Israel and Palestine with a wave of data-stealing cyber attacks. The attackers have a track record for upgrading their tools and were caught experimenting with the Poison Ivy malware in August 2013.