Google’s VirusTotal puts Linux malware under the spotlight

The rise of malware designed to infect Linux servers has earned it greater attention from VirusTotal, the Google-owned go-to tool for malware hunters.

For security researchers that need to stay on top of emerging malware threats the VirusTotal malware database has become an integral tool. Anyone can upload a suspicious file to the web tool to check whether the dozen or so antivirus engines, such as Kaspersky,McAfee, Symantec, and others, detect it as malware. 

 The tool is meant to be used by the good guys, but as one researcher found last year, black hat hackers were also using the service to test their malware against antivirus products prior to releasing it in the wild — despite the tool's shortcomings for comparative analysis.

While Virus Total maintains detailed information about malicious files affecting Windows, Linux malware has remained something of a blind spot for the tool, in part because such malware is much rarer.
The tool offered basic information about each Linux file sample, but lacked additional information that AV companies and researchers were given for Windows malware.

That situation might have been fine in the past. However, over the past two years, a new breed of Linux malware has emerged whose chief targets are not PCs but vulnerable web servers.

In part due to the lack of information, antivirus vendors were slow to respond to Linux malware samples, often submitted as ELF files — the standard binary file format for executables, object code, shared libraries, and core dumps for Unix and Unix-like systems. As such, detection rates by AV vendors remained low. Now the number of ELF files submitted is rising: in the last week alone, there were over 35,000 suspicious ELF files submitted to VirusTotal, slightly less than the 44,000 suspicious Microsoft Word files uploaded.

VirusTotal announced on Tuesday that it will be addressing the shortcomings with the web tool for Linux malware. "Even though the popularity of the Windows OS among average end-user systems has meant that attackers have mostly focused on developing malware for Windows systems, ELF badness is a growing concern," the Google subsidiary wrote in a post on Tuesday.

Read more about this Linux malware on ZDNET