Rootkits can be named the most technically sophisticated form of malicious code (malware) and one of the most difficult to discover and eliminate. Of all types of malware, probably viruses and worms get the most publicity because generally they are wide-spread and many people know to have been affected by a virus or a worm, but this definitely does not mean that viruses and worms are the most destructive malware variety. There are more dangerous types of malware, because as a rule they operate in stealth mode, are difficult to detect and remove and can go unnoticed for very long periods of time, silently stealing data and modifying the files on the victim's machine.