What was your previous AV ?
I take it that avast didn't alert on this ?
This is a rogue/fake AV, check out this slink in how to remove it,
http://www.bleepingcomputer.com/virus-removal/remove-antivirus8.
Before doing that, send a copy to avast for analysis and inclusion in its virus database.
Send the sample/s to avast as a Undetected Malware:
Open the chest (avastUI, Maintenance, Virus Chest) and right click in the Chest and select Add, navigate to where you have the sample and add it to the chest (see image). Once in the chest, right click on the file and select 'Submit to virus lab...' complete the form and submit, the file will be uploaded during the next update.
