A new worm, Sober.D, is traveling the Internet posing as a patch from Microsoft. However users should be aware that Microsoft's doesn't issue patches via email.
The worm targets users who speak German and specifically tries to propagate itself to the .nl, .be, .at, .ch, .de, and .li top level domains. The worm arrives with a file attachment that might have either an .exe or .zip file extension. Once run the attachment inserts a backdoor into the user's system, which listens on port 13468. Be sure to update your anti-virus software to guard against the new worm.