IE Defender/Files Secure/MalwareBell/IE Antivirus Codec has been update, it installs files with semi-random filenames, composed from fragment words: avg, ant, avira, safe, _sr, _ss
Files could look like: avg_sr.dll, avirasafe.dll, ant_ss.dll ...
and displays alert messages with popups:
Use SmitfraudFix to remove the infection.