Miscreants have created a strain of malware which uses memory sticks as a vector for infection.
The SillyFD-AA worm spreads by copying itself from infected machines onto removable drives such as USB memory sticks before automatically running when the device is next connected to a computer.
The malware, which is also capable of spreading through shared floppy discs, creates a hidden file called autorun.inf that ensures the malware is activated the next time infected media is plugged into a Windows PC.
Infected machines are easily recognised. The title of Internet Explorer windows on infected Windows machines is changed to include the phrase "Hacked by 1BYTE". In both its mode of infection and its lack of profit-driven motive, the SillyFD-AA worm is a throwback to the days when viruses were written for kudos rather than as part of some money-making scheme.
Net security firm Sophos predicted that the growing use of USB drives in direct mailshots and as freebies at trade shows would make them a growing vector for attack.
"With a significant rise in financially motivated malware it could be an obvious backdoor into a company for criminals bent on targeting a specific business with their malicious code," Sophos senior technology consultant Graham Cluley warned.
Firms should disable the autorun facility of Windows so removable devices such as USB keys and CD ROMs do not automatically launch when they are attached to a PC. In addition, any storage device should be checked for viruses and other malware before use. ®