The creators of the world's most complicated espionage virus Flame have sent a 'suicide' command that removes it from some infected computers.
Security firm Symantec caught the command using booby-trapped computers set up to watch Flame's actions.
Like other security firms, Symantec has kept an eye on Flame using so-called 'honeypot' computers that report what happens when they are infected with a malicious program.
According to Symantec, the 'suicide' command was 'designed to completely remove Flame from the compromised computer,' The BBC reports.
The command located every Flame file sitting on a PC, removed it and then overwrote memory locations with gibberish to thwart forensic examination.
"It tries to leave no traces of the infection behind," Symantec wrote on its blog.
Flame came to light last week after the UN's telecom body asked for help with identifying a virus found stealing data from many PCs in the Middle East.
Analysts who have investigated the virus and the pattern of infection claimed that Flame, also called Skywiper, is one of the most complex computer espionage threats ever seen.