TROJ_FAKEAV.SMEV

October 08, 2012
 Analysis by: Michael Cabel
 PLATFORM:

Windows 2000, XP, Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This Trojan executes then deletes itself afterward.

  TECHNICAL DETAILS

File Size:

Varies

File Type:

PE

Memory Resident:

Yes

Initial Samples Received Date:

16 Aug 2010

Installation

This Trojan drops the following file(s)/component(s):

  • %User Temp%\AUTMGR32.EXE - detected as TROJ_FAKEAV.SMEV
  • %User Temp%\mschrt20ex.dll - detected as TROJ_FAKEAV.BNL
  • %User Temp%\topwesitjh - detected as TROJ_FAKEAV.SMEV
  • %User Temp%\wscsvc32.exe - detected as TROJ_FRAUDPAC.LW

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.)

It executes then deletes itself afterward.

Other System Modifications

This Trojan adds the following registry entries as part of its installation routine:

HKEY_CURRENT_USER\Software
24d1ca9a-a864-4f7b-86fe-495eb56529d8 =

HKEY_CURRENT_USER\Software
7bde84a2-f58f-46ec-9eac-f1f90fead080 =

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableTaskMgr = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
DisableTaskMgr = 1

  SOLUTION

Minimum Scan Engine:

8.900

VSAPI PATTERN File:

7.389.80

VSAPI PATTERN Date:

16 Aug 2010

VSAPI PATTERN Date:

8/16/2010 12:00:00 AM

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Terminate a process file/s detected as TROJ_FAKEAV.SMEV

[ Learn More ]

*Note: If the detected file/s is/are not displayed in theWindows Task Manager, continue doing the next steps.

Step 3

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

 
  • In HKEY_CURRENT_USER\Software
    • 24d1ca9a-a864-4f7b-86fe-495eb56529d8 =
  • In HKEY_CURRENT_USER\Software
    • 7bde84a2-f58f-46ec-9eac-f1f90fead080 =
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
    • DisableTaskMgr = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
    • DisableTaskMgr = 1

Step 4

Search and delete these files

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.  %User Temp%\mschrt20ex.dll 
%User Temp%\wscsvc32.exe

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_FAKEAV.SMEV. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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