Virus writers have released yet another variant in what we must now refer to as the Sobig series.
Sobig-D, which first appeared today, is a little different from its predecessors the Sobig-B (email@example.com) and Sobig-C (firstname.lastname@example.org) worms. This time around infectious emails sent out by Sobig.D appear to come from email@example.com. The worm is spreading modestly and causing only a minimal amount of damage. Most vendors rate it as low risk.
It's still out there, though. So watch out.
Although it normally spreads via email, Sobig-D can also spread through network shares. In its more common email form, Sobig-D appears as email with randomised subject lines (such as Re: Documents and Re: Movies) and carries infectious .scr and .pif attachments. Like its predecessors, Sobig-D has a built-in expiry date - in this case July 2. Shortly thereafter we can expect another variant no doubt.
So what to do?
Well if you block email attachments such as .exe, .scr, and .pif at the gateway level, then the vast majority of worms like Sobig (in all its manifestations) need cause you no concern. For consumers, update your AV signature files, or upgrade to Linux or a Mac, whichever you find easier.
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