ZeroAccess appeared in the wild in early 2012 and shows no signs of slowing down. This insidious malware is part of a botnet which is apparently focused on clickfraud: infected computers simulate clicking on web advertisements, thereby generating ad revenue for the botnet’s perpetrators and their customers.
What makes ZeroAccess particularly nasty is that it can use a lot of bandwidth, causing infected computers to reach and surpass bandwidth caps. Unsuspecting users may find bandwidth overage charges on their ISP’s bills.
Most up to date anti-malware software can detect and remove ZeroAccess, so if you’re not already using such software, you should start. If you’ve noticed a spike in your Internet bandwidth usage, you should scan your computer immediately. Free on-line scanners such as Housecall, as well as free offline scanners like Microsoft Security Essentials will do the job.