We recently found a customer's PC infected with Alureon.A (naming may vary per anti-virus provider), a rootkit, and decided a quick tip regarding rootkits was in order.

So what is a rootkit?  The following is part of the definition from About.com (further details here): "A rootkit allows someone, either legitimate or malicious, to maintain command and control over a computer system, without the the computer system user knowing about it. This means that the owner of the rootkit is capable of executing files and changing system configurations on the target machine, as well as accessing log files or monitoring activity to covertly spy on the user's computer usage."

Rootkits by defintion aren't always bad as there are legitimate uses for them.  However, when created by malicious people, their actions can be very concerning, including the risk of identity theft.

If your computer is exhibiting bizarre or strange behavior and your anti-virus/anti-malware software has not detected an issue, we recommend running Kaspersky's TDSSKiller.  This software is a free and simple utility that will detect and remove common rootkits.  Even if your computer is not exhibiting this behavior, we recommend an occasional scan with TDSSKiller as part of your routine to keep your system healthy,