It looks like a randomly named file common for malware. What was the malware name given by avast ?
What is your firewall ?
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.
If you haven't already got this software (freeware), download, install, update and run it,
preferably in safe mode and report the findings (it should product a log file).
1.
SUPERantispyware On-Demand only in free version.
2. MalwareBytes Anti-Malware, On-Demand only in free version
http://download.bleepingcomputer.com/malwarebytes/mbam-setup.exe, right click on the link and select Save As or Save File (As depending on your browser), save it to a location where you can find it easily later.