Probably installed by Any Video Converter 2.6.2 but various other similar software on the users machine. Detected by heuristics. File attached. Malwarebytes' Anti-Malware 1.38 Database version: 2332 Windows 6.0.6001 Service Pack 1 25/06/09 2:05:21 p.m. mbam-log-2009-06-25 (14-05-21).txt Scan type: Quick Scan Objects scanned: 90082 Time elapsed: 3 minute(s), 54 second(s) Memory Processes Infected: 0 Memory Modules Infected: 0 Registry Keys Infected: 0 Registry Values Infected: 0 Registry Data Items Infected: 0 Folders Infected: 0 Files Infected: 1 Memory Processes Infected: (No malicious items detected) Memory Modules Infected: (No malicious items detected) Registry Keys Infected: (No malicious items detected) Registry Values Infected: (No malicious items detected) Registry Data Items Infected: (No malicious items detected) Folders Infected: (No malicious items detected) Files Infected: c:\Windows\System32\libmpeg2-enc-1.2.5.dll (Trojan.FakeAlert) -> Quarantined and deleted successfully. [3857535134303627615674796980888461849084857078201961323232323232323232323232323 23211152215697777] libmpeg_2_enc_1.2.5.zip libmpeg_2_enc_1.2.5.zip