Original URL: http://www.theregister.co.uk/2006/07/06/gattmann_virus/

Malware targets security research tool

The curious case of the Gattman virus

By John Leyden

Posted in Security, 6th July 2006 12:06 GMT

Virus writers have created a proof-of-concept virus, dubbed Gattman, that targets an analysis tool widely used by anti-virus researchers.

Only the most inept anti-virus researchers are likely to become infected, according to one expert, so the interest in the malware is its curiosity value rather than any threat it poses, which is virtually nil.

Gattman spreads using a program called Interactive Disassembler Pro (IDA), a popular reverse engineering tool from Data Rescue, widely used in anti-virus research labs, which converts machine code inside program files into a human-readable source code format. The tool allows the behaviour of code to be analysed.

The malware infects the scripting language used by IDA, elements of which are sometimes shared between researchers during joint analysis efforts, to create a Windows executable file. This executable searches out new IDC files to create a new executable file. Gattmann is programmed only to spread and doesn't feature any malicious payload.

Gotcha

The exchange of executable files is strictly controlled in anything approaching professionally-run security labs.

Carole Theriault, senior security consultant at UK-based anti-virus firm Sophos, said the authors of Gattman were presumably hoping to embarrass incautious researchers by spreading a virus using the very tools of their trade.

"The virus shows some technical knowledge. It was probably written in an attempt to embarrass anti-virus firms but it's unlikely to spread except among researchers - or more likely malware authors - who are both curious and careless," Theriault told El Reg. "The approach taken by the virus to spread is rather odd."

Gattman is a polymorphic virus, a technique that has fallen out of favour in recent times, which means it alters its appearance as it spreads. Both the IDC and EXE parts of this virus can change their form as they replicate. The changes in EXE files generated by Gattman use file-morphing utilities on each infected PC. Such utilities are often found on the PCs of malware researchers but uncommon more generally. ®