In what could be the beginning of a significant new trend, the operators of two separate banking botnets appear to have begun collaborating with each other in targeting systems and stealing money from victims.
Flashpoint says it has evidence suggesting the operators of the Trickbot and IcedID botnets have gotten into some kind of a profit-sharing arrangement in which they are using each other's malware and infrastructure to cash out victim bank accounts.
Such partnerships are extremely rare in the cybercrime world where rival groups are more likely to rip each other's malware out of victim systems than collaborate on a malicious campaign. For enterprises, the trend could spell new trouble.
"This collaboration indicates that sophisticated botnet malware operators will … team up to defeat anti-fraud measures in place when [a] reasonable profit-sharing agreement can be reached amongst various groups," says Vitali Kremez, director of research at Flashpoint.
According to the vendor, some malware samples that it has recently analyzed suggest that computers infected with IcedID are also downloading the Trickbot banking Trojan.
IcedID is a banking malware sample that first popped up in the wild last April and is being massively distributed via spam email. Its victims have included financial services companies, retailers, and technology firms.
Up to now, IcedID has typically been installed on systems via a downloader called Emotet. But Flashpoint says that it now appears IcedID is being sent directly as spam. When the malware is installed on a system, it then acts as a downloader for Trickbot, which in turn installs other malware modules on the compromised system.
"IcedID is a primarily banking malware with downloader capabilities to install additional malware," Kremez says. One of its key features is its ability to maintain persistence on infected machines. TrickBot is more of a multi-modular banking malware that has targeted victims in a slew of industries. The group behind it has used infected systems for a range of different malicious activities including bank account hijacking and for cryptocurrency mining.
"It is considered to be the successor to the Dyre banking malware and contains various credential-stealing, cryptocurrency mining as well as network propagation [features], amongst others," Kremez notes.
Flashpoint says the collaboration between the IcedD and Trickbot groups has given the pair significant new capabilities. The two groups are using their respective malware tools to steal credentials for breaking into bank accounts belonging to the owners of infected systems and stealing money from them.
Members from the two groups monitor infected systems for activities that are of specific interest. For instance, when the owner of a system that is infected with Trickbot and IcedID malware tries to log into a bank account of interest, the botmaster grabs the login credentials and other details and passes it on to affiliates.
The affiliates then use the login credentials and other information required to access the victim's account and transfer money out of it to rogue accounts previously opened by money mules. The mules often open the fraudulent bank accounts in the same financial institution and same geographic location as the victim's own account.
"The group botmasters collaborate on cashing out compromised bank accounts and share profits from their infections," Kremez says.
IcedID appears to be more focused on banking account-stealing operation, while TrickBot group also deploys additional modules to maximize profits from the compromised machines. Each compromised machine bears indicators of who exactly delivered the infection so it is easier to share the spoils.
Based on how the collaboration between IcedID and Trickbot has been working so far and the shared infrastructure they have built, it is quite likely that the operators of the two groups will continue to partner, Flashpoint said.
Expect to see more malware developers and fraud masters try and foster such collaborative partnerships if doing so can help them bypass the latest anti-fraud measures, the security vendor said.