Difficulty: Moderately Challenging
Step1
Make note of strange behavior on computers that were previously reliable. Look for disabled antivirus software, blue screens and system crashes and reboots. Check for new drivers, legitimate software or windows updates that coincide with this behavior. If you find none, a rootkit may be to blame.
Step2
Use free and inexpensive programs to detect rootkits. HijackThis, WinPFind and Silent Runners software are some programs that may find a rootkit. Free or beta versions of rootkit detectors and Microsoft's Malicious Software Removal Tool also can be used to look for rootkits.
Step3
Run your computer in safe mode. Do a virus scan. Some rootkits won't run in safe mode, so they're visible to the antivirus software during this time.
Step4
Combine different kinds of spyware and malware detection programs to seek out rootkits. One might find what the others did not. If you choose to keep the computer on the network, use a network analyzer or a personal firewall to detect strange activity.
Step5
Purchase a rootkit detector. You may have to use more than one, since rootkits are constantly rewritten to avoid detection by popular detectors. Check reviews on sites like PC Magazine.