Watch out for the new one. Don't click on unknown links in emails.
The worm is spread by email with a link to a seemingly innocent PDF
file or raunchy WMV download, though users who click will get much more
than they bargained for.
"When a user chooses to manually follow the hyperlink, they will be
prompted to download or execute the virus," McAfee warns. "When run, the
virus installs itself to the Windows directory as CSRSS.EXE (not to be
confused with the valid CSRSS.EXE file within the Windows System
directory). Once infected the worm attempts to send the aforementioned
message to email address book recipients."
McAfee says it can also be spread through accessible remote machines,
mapped drives, and removable media through Autorun replication. Once
infected, the virus attempts to cripple and delete security services,
including popular AV software like AntiVir, Avast, AVG, McAfee, Panda,
and a whole bunch of others.
Keep your antivirus program up to date as well as the definitions. And old antivirus program with recent definitions won't do the job.