Malware authors use rootkits to hide malware on your device, allowing malware to persist as long as possible. A successful rootkit can potentially remain in place for years if it's undetected. During this time, it will steal information and resources.
How rootkits work
Rootkits intercept and change standard operating system processes. After a rootkit infects a device, you can’t trust any information that device reports about itself.
If you were to ask a device to list all of the programs that are running, the rootkit might stealthily remove any programs it doesn’t want you to know about. Rootkits are all about hiding things. They want to hide both themselves and their malicious activity on a device.
Many modern malware families use rootkits to try to avoid detection and removal, including:
How to protect against rootkits
Like any other type of malware, the best way to avoid rootkits is to prevent it from being installed in the first place.
Apply the latest updates to operating systems and apps.
Educate your employees so they can be wary of suspicious websites and emails.
Back up important files regularly. Use the 3-2-1 rule. Keep three backups of your data, on two different storage types, and at least one backup offsite.
For more general tips, see prevent malware infection.
What if I think I have a rootkit on my device?
Microsoft security software includes a number of technologies designed specifically to remove rootkits. If you think you have a rootkit that your antimalware software isn’t detecting, you may need an extra tool that lets you boot to a known trusted environment.
Microsoft Defender Offline can be launched from Windows Security Center and has the latest anti-malware updates from Microsoft. It’s designed to be used on devices that aren't working correctly because of a possible malware infection.
System Guard in Windows 10 protects against rootkits and threats that impact system integrity.
What if I can’t remove a rootkit?
If the problem persists, we strongly recommend reinstalling the operating system and security software. Then restore your data from a backup.