Trojan.Mezzia inside avast!...?

DavidR · 2007-10-01T14:13:08.000Z

Well that is an avast file and I have it in my avast4 folder, so I suggest you check it out at one of the multi engine scanners, which is what you really should have done first, confirm detections.

You should also check the suspect file at: VirusTotal - Multi engine on-line virus scanner I feel virustotal is the better option as it uses the windows version of avast (more packers supported) and there are currently over 30 different scanners.
Or Jotti - Multi engine on-line virus scanner if any other scanners here detect them it is less likely to be a false positive. Whichever scanner you use, you can’t do this with the file in the chest, you will need to move it out.

The MD5 of C:\Program Files\Alwil Software\Avast4\AhResWS.dll is af4e5eb372f516ef061e65e8973b57b5

File properties, see image.

system · 2007-10-02T03:56:17.000Z

I’ve scanned it with VirusTotal at both date after scanning with SUPERAntiSpyware and found 0 out of 32 so that’s why I strongly believe it’s just a false positive and I’ve done nuthin’ to it. But, I still believe avast! or SUPERAntiSpyware must do s’thing to end this problem. At least, avast! team can aknowledge thier mates in SUPERAntiSpyware to fix the detection, right?

DavidR · 2007-10-02T12:18:35.000Z

MeDIeVaL post:3:

I’ve scanned it with VirusTotal at both date after scanning with SUPERAntiSpyware and found 0 out of 32 so that’s why I strongly believe it’s just a false positive and I’ve done nuthin’ to it. But, I still believe avast! or SUPERAntiSpyware must do s’thing to end this problem. At least, avast! team can aknowledge thier mates in SUPERAntiSpyware to fix the detection, right?

It isn’t an avast problem but a false positive detection of a legitimate avast file so you need to report it to SAS as it is their problem to resolve.
avast can’t do anything as it doesn’t know what it is that is causing SAS to alert.

I have no idea if there is any communication between SAS and Alwil software.

system · 2007-10-03T01:55:08.000Z

Strange, SAS reports the file as clean on my system. ???

Vladimyr · 2007-10-03T02:33:55.000Z

Jahn post:5:

Strange, SAS reports the file as clean on my system. ???

Mine too ???

system · 2007-10-03T11:10:47.000Z

This screenshot I’ve taken this evening as SAS asked me to submit the sample…

http://www.geocities.com/solutem/avast.JPG

Lisandro · 2007-10-03T12:18:15.000Z

No troubles here…
Are you sure your avast installation is not compromised?
Is SAS fully updated?

system · 2007-10-03T15:11:45.000Z

Nope, there’s no compromise in avast! installation. The detection only occur start from 25/09/07 as I scan my system weekly with every security application. As you can see the SAS were up to dates. I’ll check for the updates almost e’day…

Bluesman · 2007-10-03T17:44:25.000Z

Tech post:8:

No troubles here…

Same here, just checked, no problems at all.

system · 2007-10-03T18:07:35.000Z

SAS only detect the trojann when I’ve done full system scanned. If I right clicked the file and scanned it found nuthin…

Lisandro · 2007-10-03T18:25:33.000Z

MeDIeVaL post:11:

SAS only detect the trojann when I’ve done full system scanned.

I’ve done that, I mean, just for that folder but the deepest scanning… Am I wrong? Is there any wrong setting on my installation?

system · 2007-10-03T20:44:43.000Z

MeDIeVaL, is this the same system that had the trojan downloader?
http://forum.avast.com/index.php?topic=30525.msg253810#msg253810

I’m wondering if it compromised Avast and/or SAS. Did you verify the MD5 of %:\Program Files\Alwil Software\Avast4\AhResWS.dll to the one DavidR posted in reply #1? Mine has the correct MD5 and is clean as I stated.

(Edit: Added:) SAS started detecting the Avast file right after the downloader was detected.

system · 2007-10-03T20:50:16.000Z

Tech post:12:

I’ve done that, I mean, just for that folder but the deepest scanning… Am I wrong? Is there any wrong setting on my installation?

Tech, I would think the context menu scan would be the most thorough. I only found two scanner options in SAS that weren’t set to maximum (Ignore non-executable files and Ignore files larger than 4 MB), but even after changing them, a full system scan came out clean.

DavidR · 2007-10-03T21:28:52.000Z

Jahn post:13:

MeDIeVaL,
I’m wondering if it compromised Avast and/or SAS. Did you verify the MD5 of %:\Program Files\Alwil Software\Avast4\AhResWS.dll to the one DavidR posted in reply #1? Mine has the correct MD5 and is clean as I stated.

You are right to press for this check as it is critical and the reason I posted it in the same opst as the VT and Jotti links is because the MD5 of the file is part of the information provided on the VirusTotal scan. So yes it would be nice if MeDIeVaL would confirm this.

system · 2007-10-04T01:57:42.000Z

Jahn post:13:

MeDIeVaL, is this the same system that had the trojan downloader?
http://forum.avast.com/index.php?topic=30525.msg253810#msg253810

I’m wondering if it compromised Avast and/or SAS. Did you verify the MD5 of %:\Program Files\Alwil Software\Avast4\AhResWS.dll to the one DavidR posted in reply #1? Mine has the correct MD5 and is clean as I stated.

(Edit: Added:) SAS started detecting the Avast file right after the downloader was detected.

Nope, not the same system. That’s my friend pc actually (as I do a part time job repairing and upgrading pc). This prob just occur to my own pc, never had this prob before 25th Sep. I’ve submitted the sample to SAS hoping that they will give the positive feedback 'bout this. Actually, this prob has do no harm to my pc except I’m afraid if I accidently put the suspected file into quarantined or worst delete it. I’m in my office right now, I would cx the MD5 after I’m getting back from work.

system · 2007-10-04T04:06:44.000Z

Here the MD5 for avast!

Additional information
File size: 53248 bytes
MD5: af4e5eb372f516ef061e65e8973b57b5
SHA1: 5cda88f692618d44aa238a4f673671ef28045510

DavidR · 2007-10-04T12:13:32.000Z

Which is the same as the one I posted.

The MD5 of C:\Program Files\Alwil Software\Avast4\AhResWS.dll is af4e5eb372f516ef061e65e8973b57b5

So your file is the same as mine and it hasn’t been changed.

system · 2007-10-04T21:15:07.000Z

Sounds like it’s up to SAS now to offer an explanation.

system · 2007-10-05T20:44:43.000Z

Just finished full scanning my system with SAS. It seem the problem solved with SAS latest update… Don’t have the false positive alarm detection anymore

system · 2007-10-05T22:26:14.000Z

MeDIeVaL post:20:

Just finished full scanning my system with SAS. It seem the problem solved with SAS latest update… Don’t have the false positive alarm detection anymore

Glad you got it sorted, MeDIeVaL.

I’m still curious why SAS would detect the same file as positive on one system, but not on others. I saw on their forum they didn’t give you an explanation (they usually don’t), so I guess I’ll never know. ???

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