UK businesses warned of hybrid virus

Anti-virus experts have warned UK businesses of worm/virus hybrids may attack their computer systems.

W32/Klez-E is a Win32 worm which spreads via email attachment. The worm carries a compressed copy of the W32/ElKern-B virus inside, which it executes once the file is opened.

The worm is able to search for email address entries in the Windows address book and emails a copy of itself to every address.

Anti-virus specialist Sophos said the email will have the following characteristics:

"The subject line is either random or chosen from a long list of different choices. The message text is randomly composed by the worm but the message can also be without a text. Attached file: Randomly named with extension .PIF, .SCR, .EXE or .BAT."

The W32/Klez-E worm tries to disable most anti-virus products and delete some anti-virus related files.

Sophos said the virus isn't prolific at the moment, but reminded users to check their AV protection is up-to-date.