A rootkit, like a cloak of invisibility, is a program that conceals the presence of an application on a computer.
Installing itself silently, it stays concealed by hiding processes, files, network traffic and other observable information about itself from the computer user. Rootkits typically hide utilities that make it easy for attackers to return to a compromised system. Rootkits aren't easily detected and since no single vendor reliably detects all rootkits, it can be beneficial to work with more than one free rootkit tool.
Sophos Anti-Rootkit is a sophisticated rootkit detector and remover for Windows NT, 2000, XP and 2003. Before scanning, it's strongly recommended to close down all non-essential applications. A rootkit scan can take several minutes on a desktop computer or significantly longer on a server. The scan searches for hidden files, processes, registry keys and values. When the scan finishes, a pop-up screen appears, confirming the status and results of the scan. Click on the suspicious file to display more information about it. The information displayed includes whether the item is recommended for removal. If a suspicious file is recognized it can be safely removed, and if the scanner isn't sure what it is, but considers it suspicious, it can still be removed.
If one of the rootkit scanners mentioned above doesn't do it for you, you can also run additional rootkit detection and removal tools such as:
McAfee Rootkit Detective is a program designed to detect and clean rootkits and works on XP, 2000 and 2003. However, McAfee strongly recommends its software only be used by knowledgeable individuals at the direction of, and with the support of a representative from McAfee Avert Labs or McAfee Technical. AVG Anti-Rootkit Free provides for rootkit detection and removal and works on Windows 2000 and XP.
Rootkit detection and removal is showing up as part of more anti-virus packages, but these scanners can help provide an additional line of defense against the dark arts.
About the author:
Scott Sidel is an ISSO with Lockheed Martin.