The lab’s standard anti-virus software, Sophos, is continually updated with the latest information about viruses. Today at 1:20pm, Sophos released an update which is causing many clients to incorrectly report they are infected with Shh/Updater-B. If you receive one of these warnings it is safe to ignore it. We are actively working on the problem and mitigation.
There is now a fix available - please visit http://go.lbl.gov/sophos