Security researchers warned that the cybercriminals behind the two banking Trojans are now collaborating to perform man-in-the-middle (MitM) attacks.

On March 17, Crowdstrike discovered a BokBot proxy module called shadDll in conjunction with TrickBot. The code for the two banking Trojans is 81 percent similar, the researchers said, which means the proxy module can be seamlessly integrated into TrickBot’s extensible, modular framework. It’s possible the two threat groups have been collaborating on an ongoing basis, the researchers added.

Adding New Features Through Threat Group Collaboration

After infecting a machine by duping victims into installing malware via phishing messages, TrickBot can use the shadDll module to access networking functions and install illegitimate secure socket layer (SSL) certificates. At this point, it can do many of the things BokBot can do, including intercepting web traffic and redirecting it, taking screenshots to steal personal information, and injecting other malicious code.

The researchers have attributed the BokBot Trojan to a cybercriminal group called Lunar Spider, while TrickBot is believed to have been created by a group called Wizard Spider. TrickBot, which first emerged in late 2016, has proven highly versatile in attacking financial services firms, and Wizard Spider may include members of the group that developed the earlier Dyre malware, according to Crowdstrike.

How to Stay Ahead of TrickBot’s Tricks

The “IBM X-Force Threat Intelligence Index” for 2019 identified TrickBot as the most prevalent financial malware family of last year, representing 13 percent of all campaign activity. This was in part due to the ability of various threat actors to make use of the Trojan’s variants. For example, the report showed that IcedID distributed TrickBot within its own botnet in a 2018 campaign. However, experts noted that proper security controls, regular user education and planned incident response can help keep this threat at bay.

X-Force researchers also discovered that TrickBot has been used to steal cryptocurrency, and distribution of the BokBot module may make it even more popular. Organizations should employ advanced malware protection to receive alerts for high-risk devices and notifications when malware has been detected to ensure this cooperation among cybercriminals doesn’t lead to even deadlier attacks.