Mobile security researchers are warning of a new virus that attempts to infect personal digital assistants (PDAs) once it has found its way onto a Windows PC.
The Crossover bug has been sent anonymously to the Mobile Anti-virus Researchers Association. The proof-of-concept bug has not so far been released into the wild, so as yet there is no actual risk to PC and mobile device users.
But the research association said the bug was the first malware to be able to infect both a Windows desktop computer as well as a PDA running Windows Mobile for Pocket PC systems.
When executed, the virus checks what type of machine it is running on. If it running on a Windows PC, it will try and jump to a handheld device as soon as it detects a connection using Microsoft's ActiveSync synchronisation software.
When it runs on a portable operating system it will erase all files in the My Documents folder and copy itself to the start-up folder.
The virus can harm the performance of a Windows PC because it re-creates itself each time the PC is started. This can mean a user will end up running multiple copies of the program, meaning the system can become bogged down.
Security software firm F-Secure reported a Trojan horse last September that attempted to spread from smart phones to users' PCs, but Crossover is believed to be one of the first times the crossover infection attempt has been the other way round.