'Quarter' of TWO-MILLION-strong zombie PC army lured to their deaths
Pied piper Symantec says it led infected computers into sinkhole
Symantec has claimed credit for luring a significant lump of the powerful ZeroAccess botnet into a sinkhole.
ZeroAccess has been active since 2011 and is one of the largest known botnets in existence: it has upwards of 1.9 million infected computers forming its army, all remotely controlled by miscreants. This swarm of PC robots is put to work generating tens of millions of dollars annually, it is estimated.
It's claimed crooks make money from the infected Windows machines by instructing the computers to virtually (and fraudulently) click on web adverts, thus ramping up income for an affiliate ad network, or (to a lesser extent) mine for new Bitcoins.
By subverting the communications system used by the bots to organise, Symantec has sinkholed - gained control or disabled, in other words - more than half a million bots, we're told.
This will have made a serious dent in the number of zombie drones under the thrall of the ZeroAccess gang. Symantec said it is working with ISPs and government computer security teams (CERTs) worldwide to help get infected machines cleaned up.
ZeroAccess infects Microsoft-powered computers caught up in drive-by-downloads: booby-trapped websites attempt to exploit security holes in web surfers' machines to install the malware. It then uses a rootkit to hide itself from the operating system and the victim, set itself up on a secret file system, downloads yet more software nasties, connects to other infected systems and opens up backdoor access.
The ZeroAccess botnet is sophisticated and resilient, using a peer-to-peer architecture to communicate. Thus, it enjoys a high degree of redundancy and no central command-and-control server for the good guys to target. As a result nobody is under any illusions that Symantec's action has finally put paid to the zombie network.
More details on the takedown effort can be found in a blog post by Symantec here. ®