Sobig

Sobig is a worm that was especially prominent in 2003, the year in which Sobig was distributed through e-mail spam (a relatively innovative technique for the time). Although Sobig worms were configured to deactivate themselves after that year, SpywareRemove.com malware experts note that inactive copies of Sobig can still be security risks for your computer – especially since some variants of Sobig have been known to create backdoor vulnerabilities. These vulnerabilities can lead to other attacks against your computer and should be considered significant security breaches. Although Sobig's primary place remains in the history books for malware, inactive copies of Sobig still should be deleted by appropriate anti-malware products if you have any reason to think that Sobig may be on your computer.

Back When Sobig Was So Very Big on the Internet

Sobig, like many of the earliest worms, was designed just for the primary purpose of distributing itself. SpywareRemove.com malware analysts are familiar with six distinct variants of Sobig: Sobig.A, Sobig.B, Sobig.C, Sobig.D, Sobig.E and Sobig.F. Prior to Sobig.F (which was the most prolific of these variants), Sobig worms often installed WinGate proxy software and used said software to create backdoor vulnerabilities. Sobig.F also included downloading and self-updating capabilities. These functions were often (but not solely) used with SMTP e-mail clients that could distribute Sobig through malicious e-mail messages.

Sobig gathered e-mail address information from infected PCs to determine new targets for its e-mail spam. This spam included generic subject lines such as 'Re: Details' or 'Thank you!' along with a copy of Sobig as a file attachment. The Sobig file attachment was displayed in a PIF format, a DOS-dependent format that's considered outdated. Although it's unlikely that new e-mails carrying Sobig ever will appear, SpywareRemove.com malware researchers are forced to note that there's no reason why Sobig couldn't install itself from an old, undeleted e-mail if, in fact, any still exist.

Why Size of Impact Doesn't Help You See the Big Picture

Sobig holds a significant position in history, both due to its e-mail distribution strategy and due to how widespread Sobig was – with Microsoft eventually offering a reward of over two hundred thousand dollars to anyone who could assist with the arrest of Sobig's coder. At this time, it's unlikely that Sobig will make a comeback, but SpywareRemove.com malware researchers have every reason to emphasize that similar techniques – social engineering content, e-mail address theft, concealed spamming attacks and backdoor exploits – all are in popular use by other, more modernized PC threats than Sobig.

Sobig doesn't have any obvious symptoms, and anti-malware software can be necessary for you to be vapable of removing Sobig safely. However, active PC threats that engage in spamming attacks (including Sobig prior to its deactivation) often cause poor system performance due to their high usage of RAM and other resources. SpywareRemove.com malware experts recommend that you scan your PC, just to be safe, if you experience noticeable drops in performance that refuse to resolve themselves.