That is malware - locate the file from the Avast chest and upload as a suspicious file

THEN

Download OTL to your Desktop

[*]Double click on the icon to run it. Make sure all other windows are closed and to let it run uninterrupted.
[*]Select All Users
[*]Under the Custom Scan box paste this in
netsvcs
%SYSTEMDRIVE%*.exe
/md5start
explorer.exe
winlogon.exe
Userinit.exe
svchost.exe
/md5stop
C:\Windows\assembly\tmp\U*.* /s
CREATERESTOREPOINT

[*]Click the Quick Scan button. Do not change any settings unless otherwise told to do so. The scan wont take long.
[*]When the scan completes, it will open two notepad windows. OTL.Txt and Extras.Txt. These are saved in the same location as OTL.
[*]Attach both logs