Malwarebytes' Possible Steam False Positive?

[Respital]

After a routine scan i was surprised to find that Malwarebytes' had actually found something on my computer. Looking at the results, it supposes that there is a "Trojan.Fakesig in my Steam files. A quick Google search hasn't found anything and I haven't encountered any viruses which hide in Steam before.

Malwarebytes Anti-Malware 1.65.0.1400
www.malwarebytes.org

Database version: v2012.10.06.05

Windows 7 Service Pack 1 x64 NTFS
Internet Explorer 9.0.8112.16421
AdministratorX :: ADMINISTRATORII [administrator]

10/6/2012 3:06:00 PM
mbam-log-2012-10-06 (15-12-00).txt

Scan type: Quick scan
Scan options enabled: Memory | Startup | Registry | File System | Heuristics/Extra | Heuristics/Shuriken | PUP | PUM
Scan options disabled: P2P
Objects scanned: 198317
Time elapsed: 1 minute(s), 25 second(s)

Memory Processes Detected: 0
(No malicious items detected)

Memory Modules Detected: 1
C:\Program Files (x86)\Steam\bin\avutil-51.dll (Trojan.Fakesig) -> No action taken.

Registry Keys Detected: 0
(No malicious items detected)

Registry Values Detected: 0
(No malicious items detected)

Registry Data Items Detected: 0
(No malicious items detected)

Folders Detected: 0
(No malicious items detected)

Files Detected: 1
C:\Program Files (x86)\Steam\bin\avutil-51.dll (Trojan.Fakesig) -> No action taken.

(end)

Malwarebytes Anti-Malware 1.65.0.1400
www.malwarebytes.org

Database version: v2012.10.06.05

Windows 7 Service Pack 1 x64 NTFS
Internet Explorer 9.0.8112.16421
AdministratorX :: ADMINISTRATORII [administrator]

10/6/2012 3:12:23 PM
mbam-log-2012-10-06 (15-33-17).txt

Scan type: Full scan (C:\|)
Scan options enabled: Memory | Startup | Registry | File System | Heuristics/Extra | Heuristics/Shuriken | PUP | PUM
Scan options disabled: P2P
Objects scanned: 308644
Time elapsed: 19 minute(s), 47 second(s)

Memory Processes Detected: 0
(No malicious items detected)

Memory Modules Detected: 1
C:\Program Files (x86)\Steam\bin\avutil-51.dll (Trojan.Fakesig) -> No action taken.

Registry Keys Detected: 0
(No malicious items detected)

Registry Values Detected: 0
(No malicious items detected)

Registry Data Items Detected: 0
(No malicious items detected)

Folders Detected: 0
(No malicious items detected)

Files Detected: 2
C:\Program Files (x86)\Steam\bin\avutil-51.dll (Trojan.Fakesig) -> No action taken.
C:\Program Files (x86)\Steam\avutil-51.dll (Trojan.Fakesig) -> No action taken.

(end)

Virustotal Scan:

https://www.virustotal.com/file/ae4...38423118bca3ecbe2d376be6/analysis/1349552192/

 

[Respital]

It looks like just a false positive on Malwarebytes' end, no need for alarm that i can tell.

 

[technewbie]

at 3:06 AM 10/7/12 (UTC+8:00)

just opened my laptop and updated virus definitions of malwarebytes, then started a quick scan, and suddenly found that too, C:\Program Files (x86)\Steam\bin\avutil-51.dll (Trojan.Fakesig), quarantined the item until i can research if its a threat or if its safe, any info would be much help, im playing dota 2, dont know if the trojan infected my computer because of recent steam updates or this is only a false positive result. By googling this issue, i found this forum, and based on the time of post, this trojanfakesig was only detected today so im still waiting for replies, thank you for those who will help

 

[claptonman]

http://forums.malwarebytes.org/index.php?showtopic=117000

I'd wait till the mods there relay info from the developers.

Just did a scan, showed up on mine, too.

 

[technewbie]

restored my quarantined avutil-51.dll and rescanned steam folder, found nothing as malwarebytes staff said that should be fixed on the new update, marked as false positive. good thing they acted it immediately

/close thread