If it keeps coming back, there is likely to be an undetected or hidden element to the infection that restores or downloads the file again. What is your firewall ?
If you haven't already got this software (freeware), download, install, update and run it and report the findings (it should product a log file).
Don't worry about reported tracking cookies they are a minor issue and not one of security, allow SAS to deal with them though. - See
http://en.wikipedia.org/wiki/HTTP_cookie.
Note:
If either find files that they state are infected, first copy the file to the avast chest User Files section and send to avast to improve overall detection.
Add the file to the User Files (File, Add) section of the avast chest 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 (allow MBAM/SAS to remove/quarantine it/them).
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.
