"What's worse than finding spyware and viruses on your computer? Finding out that the software you use to keep your computer safe may be just as dangerous.
Symantec, makers of the popular Norton AntiVirus protection software and numerous other products, routinely hides a "rootkit" in its Norton SystemWorks program suite.
The rootkit was designed to prevent SystemWorks users from mistakenly deleting files necessary to run the program suite, but the rootkit also hides the files from antivirus scans. Clever hackers could use the security hole to upload viruses into a computer without being detected."
Article: Consumer Affairs