Security researchers have discovered that the Emotet Trojan is still active and becoming more sophisticated and successful in how it spreads through corporate systems.

Security researchers from Check Point reported on July 24 that the Emotet Trojan, which was first discovered in 2014, is still active. Unlike other bots and malware that make headlines for a short time before they disappear, Emotet has proven surprisingly durable.

It initially acted as a banking Trojan focused on stealing financial information. While the researchers highlighted that the banking functionality was removed in 2017, its modular design has allowed it to infect networks through the Rig exploit kit, network shares and more traditional means, such as spam email messages.

Emotet Trojan Develops an ‘Ecosystem of Modules’

The Emotet Trojan directly hooks network application programming interface (API) functions to gather data, such as login credentials rather than browser functions. But more recently it has used third-party open source code to set up what researchers described as an “ecosystem of modules.”

The main dropper, for example, allows the Trojan to immediately upgrade itself to the latest version of the malware and rotate the command and control (C&C) servers it uses to send stolen information back and forth. For security professionals, this makes detection even more elusive because standard antivirus tools typically do not match patterns within files to identify them as malicious. According to a recent US-CERT bulletin, the Trojan has cost various government organizations an average of $1 million per incident.

How a Threat Hunting Program Can Help Protect Against Persistent Malware

As the actors behind the Emotet Trojan and similar threats become more effective in getting past perimeter defenses, chief information security officers (CISOs) and their teams should focus on protecting against malware that gains persistence and strengthens its foothold in the network, according to IBM Security experts.

According to the IBM X-Force Incident Response and Intelligence Services (IRIS) cyberattack framework, security leaders should develop a threat hunting program to proactively scan networks for signs of persistence and expand the scope as necessary to mitigate further infection. By prioritizing telemetry data into tiers of both benign and potentially malicious activities via a logging and analysis platform, meanwhile, security teams can more efficiently stop threats like the Emotet Trojan in their tracks — no matter how they evolve.

Source: Check Point, US-CERT