Like worms that have attacked MSN Messenger, AOL IM and Yahoo Messenger in the recent past, a worm is currently attacking Skype IM users. From an infected machine, the virus known as either Ramex.a (Skype) or Pykspa.a (McAfee) or Skipi.a shoots messages with a live link to people on the infected machine's Skype contact list. A JPEG image within the message provides a download link to a file with the SCR extension. Recipients who click on the link are then infected.
Once installed, the worm injects bogus entries into the computer's HOSTS file so that security software cannot update itself. The worm may also add applications to the approved programs that work with the Skype list. More sinister, one of the installed programs attempts to steal sensitive information from the infected machine.
Skype users are advised to be wary when opening links sent by instant messaging. Most antivirus programs will now protect Skype users from infection.