The anti-rootkit module in avast is based on the gmer anti-rootkit engine, though I don't know if it uses that name of an avast based file name. Though your version is different to mine(1.0.14.4401, see image.
Now I don't know if that may have anything the version of avast you are using and your signature is very short on information it has taken ages to get you to post that.
When asking for help the information in your signature (or lack of it) directly assists those who try to help. I can't understand the reluctance to do that.