RSA Warns Of Zero Detection Trojan

It’s apparently not just zero-day vulnerabilities that organizations need to worry about these days, but also zero detection malware threats.

For the second time in recent weeks, a security vendor has issued a warning about a malware tool that appears to have evaded detection for multiple years while stealthily going about targeting victims.

The malware, called GlassRAT, appears to have been released back in 2012. The limited telemetry and anecdotal reports that are available on it indicate that GlassRAT has been used to target Chinese nationals at large multinational companies, RSA Research said in an alert released this week.

The “zero detection” malware, which is signed with a digital certificate apparently misappropriated from a Chinese software developer, is “transparent” to most antivirus tools, RSA researchers said in the report. It is detectable only via network forensics and specialized tools that are capable of detecting suspicious activity on endpoint systems, they said.

“GlassRAT appears to have operated, stealthily, for nearly 3 years in some environments,” the paper noted.

The RSA researchers described GlassRAT, as a well-designed remote access trojan that is being used in a highly targeted manner. The dropper used to deliver the payload is digitally signed and deletes itself from the system after its task is complete.  Once installed, the malicious file itself remains below the radar of endpoint anti-malware tools.

The malware provides reverse shell functionality on an infected system allowing the threat actors behind GlassRAT to directly connect to it from a remote location. The malware is designed to steal data, transfer files and relay system information to the attackers.

 “What makes GlassRAT notable is not what it is, but perhaps rather where it came from, who is using it, and for what purpose," the researchers said.

Available information on GlassRAT suggests that it is connected to, or at least has used the same command and control infrastructure that other malware campaigns in the past have used to target organizations of strategic and geopolitical significance, the RSA researchers said.

Two domains associated with GlassRAT for instance, were previously associated with the Mirage and PlugX campaigns that targeted military and government organizations in Mongolia and the Philippines. The overlap window is fairly small suggesting that the threat actors behind GlassRAT may have made an operational slip in using the same infrastructure.

The threat represented by malware like GlassRAT should not be underestimated because there may be many more undetected or non-detectable samples like it in the world, the researchers said. “ It is also crucially important to recognize the potential origins of these attacks, when detected, to better understand risks to the organization.”

GlassRAT marks the second time this month when a security vendor has warned about a malware threat that remained undetected for a lengthy period. Earlier this month, Trustwave issued an alert on Cherry Picker, a point of sale malware tool that like GlassRAT remained below the radar for more than four years before being discovered.

Trustwave pointed to Cherry Picker’s use of encryption, modified configuration files and sophisticated obfuscation techniques as reasons why the malware remained undetected for so long. According to researchers at the company, no malware they have encountered goes quite as far as Cherry Picker does in cleaning up after itself after infecting a system.