IT security experts have warned of a worm that purports to be Microsoft's Windows Genuine Advantage (WGA) anti-piracy tool. The Cuebot-K worm spreads via AOL Instant Messenger, registering itself as a new system driver service called 'wgavn'. It carries the display name 'Windows Genuine Advantage Validation Notification', and runs automatically during system startup. Users who view the list of services are told that removing or stopping the service will result in 'system instability'. Once in place the worm disables the Windows firewall, and opens a backdoor to infected computers which allows hackers to gain remote access, spy.