The Malwarebytes' Anti-Malware is quite effective against this, if it detects any files associated with rogue security programs, etc. that avast hasn't detected before you deal with them using MBAM, send a copy to the avast Chest, User Files section, see below, the original remains in place and can then be dealt with by MBAM.
Submit the sample to avast as undetected malware:
Add the file to the User Files (File, Add) section of the avast chest (if it isn't already there) where it can do no harm and send it from there. A copy of the file/s will remain in the original location, so you will need to take further action and can remove/rename that.
Send it from the User Files section of the chest (select the file, right click, email to Alwil Software). It will be uploaded (not actually emailed) to avast when the next avast auto (or manual) update is done.
