Beware - a brand new malware family is infecting Linux systems

Trojan
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There’s a new malware (opens in new tab) family in town - and one that attacks Linux systems (opens in new tab) by concealing itself in legitimate binaries to deliver several backdoor and rootkits.

Dubbed FontOnLake, by cybersecurity (opens in new tab) researchers at ESET (opens in new tab), samples of the malware date as far back as May 2020.

According to the researchers, the malware makes use of several carefully crafted modules that not just collect credentials, but also give remote access (opens in new tab) to the threat actors.

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“The sneaky nature of FontOnLake’s tools in combination with advanced design and low prevalence suggest that they are used in targeted attacks,” believes (opens in new tab) Vladislav Hrčka, malware analyst and reverse engineer at ESET.

Trojanized utilities

Hrčka notes that all the malware disguises itself inside trojanized versions of standard Linux (opens in new tab) utilities, including cat, kill, and sshd. In fact, one of the samples the researchers analyzed was created specifically for CentOS (opens in new tab) and Debian.

However, the exact mechanism employed by the threat actors to replace the original utilities with the malicious ones remains a mystery.

Analyzing the malware, the researchers note that the samples contained three custom backdoors written in C++, which gave remote access to the infected machines to the operators of the malware.

The location of the Command and Control (C2) server and the countries from which the samples were uploaded indicate that the attackers were after targets based in Southeast Asia.

“Following our discovery while finalizing our white paper on this topic, vendors such as Tencent Security Response Center (opens in new tab), Avast (opens in new tab) and Lacework Labs (opens in new tab) published their research on what appears to be the same malware,” notes Hrčka, adding that ESET’s products can flag all the components of the malware. 

With almost two decades of writing and reporting on Linux, Mayank Sharma would like everyone to think he’s TechRadar Pro’s expert on the topic. Of course, he’s just as interested in other computing topics, particularly cybersecurity, cloud, containers, and coding.