4images_ms.exe is injection win32 worms..
there is no worms in this software.
4images_ms.exe is
UPX compressed, and many antivirus software can't handle properly such compression and throwing false positive warnings (I even heard is that because most malware is using that compression, so any legit software automatically get into that category too).
You can see the difference in how many false-positive antivirus programs report and file sizes between original
4images_ms.exe (674,092 bytes) and
unpacked (no UPX compression, 1,416,492 bytes)
I've attached unpacked (used
upx.exe -d 4images_ms.exe) version, see if your antivirus still confused.
P.S.
Personally I lost any faith in Avast antivirus after it started giving me a hard time regarding a javascript I was writing...it's one of the most false-positive antiviruses I know of...