Hitman Pro comes with a hidden rootkit service to address sophisticated rootkits. This program should rather be run under the supervision of a qualified malware remover as the unprofessional use of it could lead to serious damage to your computer. That is why this is generically flagged as a possibly unwanted program. Problem was also addressed in this thread, see: http://forum.avast.com/index.php?topic=100050.0

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