How to stop Trojan:win32/Dynamer!ac from coming back

Anonymous
2016-02-02T00:30:56+00:00

Hi all,

Windows Defender found Trojan:win32/Dynamer!ac virus during a full scan - and I keep quarantining and removing it and it keeps coming back. It is in my D: drive on HP Notebook -  the Recovery Drive and I can't remove anything - is this real or a false positive? If it’s real how do I remove it?

I’m on Windows 8.1 Here’s the infected file – that I can’t access

Items:

containerfile:D:\preload\install.wim

file:D:\preload\install.wim->(Image20548)\Program Files (x86)\WildGames\House of 1000 Doors Family Secrets\HouseOf1000Doors_FamilySecrets-WT.exe->(EXEEmb)->(EXEEmb)

Spybot- Avast - TDSSKiller - Malwarebytes - and RKill couldn't find it.

Any help would be greatly appreciated.

Windows for home | Previous Windows versions | Security and privacy

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Anonymous
2016-02-29T22:38:53+00:00

Barnes99  said on February 24, 2016:

Problem solved! Yesterday, I did another update and scan with Windows Defender, and the scan did NOT find the Trojan:win32/Dynamer!ac virus. This forum and patience with MS has apparently paid off. Again, in my case, I am talking about an HP 2000 Notebook PC with Windows 10. HIP HIP Hurray! Has anybody else's luck with this changed, recently?

=====

dreamWheasler replied on February 24, 2016:

Yes! I, too, ran two scans:

  1. Windows Defender Custom - just on "D:\preload" (where Dynamer!ac had been roosting) = clean!
  2. Windows Defender Full (w/ no exclusions) = clean!

. . . also, no other threats were found.

Thank you both for your feedback.

No 'official' confirmation but it seems that starting with definition version 1.213.6922.0 (and above) made available on Feb 23, 2016 at 03:48 AM UTC, the problem has been solved indeed (updated definitions for Dynamer!ac).

At the time of this post, the latest definitions are 1.213.7574.0, dated: Feb 29, 2016 9:19 PM UTC.

You may now take off the temporary exclusion previously set for the recovery partition [1].

Hope all is well now for everyone on this thread.

=========================================================

[1] Good time to review Monkey's suggestions in this thread regarding the 'obsoleteness' of such RP.

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Anonymous
2016-02-20T20:15:27+00:00

Thanks for your feedback.

FWIW... Re-posting/Re-phrasing from previous posts and/or related threads:

The suspected FP detection is of a pattern of bits within a compressed recovery partition file that matches bits for software classified as malware, but it wouldn't be active or running where located anyway.

Signatures are updated regularly to detect new malware, so it would appear there is something about the current signatures that are now detecting that bit of code in your backup image as the subject malware. That is believed to be a false positive, but since we can't be 100% sure - and MS is taking their time to revert with a fix (if any - updated definitions) - that's why I suggested earlier to run a few other scanners to confirm if it is false or not.

Whilst awaiting for someone from the Team to come by to confirm it (or not) or otherwise state how to proceed to remove subject threat, my recommendation still being to be patient and follow the advice to exclude that location from scanning rather than trying to remove the affected file you can't access anyway. You may wish to exclude only the image file rather than the entire restore partition since there is no reason to, when the problem is only one file and excluding that will suffice to stop the 'noice'.

Hope this helps.

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Monkey57 3,535 Reputation points
2016-02-17T13:46:22+00:00

While it may be a false positive, I do not suggest treating it as such, until if it has been declared as such, from your antivirus mfg.  The area of concern, is non-critical, and mfg suggest you make a off-line restore media, also.  I suggest removing the restore partition, even if is not reporting suspicious files.

Please see Create a Recovery Drive-

http://answers.microsoft.com/en-us/protect/forum/protect_defender-protect_scanning/how-to-stop-trojanwin32dynamerac-from-coming-back/9776b54b-bdac-4517-a7c4-c5dcae240ec4?page=3

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  1. Anonymous
    2016-08-15T11:28:40+00:00

    MSE will remove trojan:win32/dynamer!ac when scanned first time.bUt if u scan again it will show same virus on same location. I thing even microsoft dont have solution for it.

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  2. Monkey57 3,535 Reputation points
    2016-03-17T17:09:28+00:00

    What is the Make/Model of your computer?  

    Have you backed up the recovery partition as recommend by most mfg, from their continuing reminder prompts?

    If you have upgraded the computer from the original operatings system ( (i.e. 8-8.1 or 7,8.1-10).

    Please consider using the mfg tool to back up the recovery partition and delete it; or create a usb recovery drive, and delete the recovery partiton off the computer:

    http://windows.microsoft.com/en-us/windows-8/create-usb-recovery-drive

    See instructions within the mfg recovery app or on their website for options of what to do with the old pre-installed recovery partition. (If ava. delete the old pre-installed partition).

    or

    1. Type CREATE A RECOVERY DRIVE into the search box (in Windows 8 or 10) and select it. Confirm your choice, or enter admin. password if necessary.
    2. When the tool opens be sure that BACK UP SYSTEM FILES TO THE RECOVERY DRIVE is selected, then select NEXT.
    3. Connect your USB, select it, then select NEXT > CREATE.
    4. When it is done, you will see an option to "Delete the Recovery Partition." If you want to free up drive space on your PC choose this and Delete. If not, select Finish.

    (from mmwillie4 - http://answers.microsoft.com/en-us/windows/forum/windows_8-update/usb-flash-drive-not-a-valid-backup-location-for/6f146373-3052-46a5-8648-e9a177ea5fca?page=5

    With the Win10 reset capabilities, you will probably never use the created 'usb recovery drive', but you will have it just in case.

    This will stop the pre-installed potentially out-of-date/unsupported versions of software in a Recovery Partition, from setting off the antivirus software.  And give you an extra recovery method, if your hard drive crashes.

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