TROJ_AGENT.HSC

October 08, 2012
 Analysis by: Christopher Daniel So
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

It adds registry entries as part of its installation routine. It drops the files.

This Trojan may be dropped by other malware.

  TECHNICAL DETAILS

File Size:

36,864 bytes

File Type:

PE

Memory Resident:

Yes

Initial Samples Received Date:

27 Dec 2010

Arrival Details

This Trojan may be dropped by other malware.

Other System Modifications

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

HKEY_CURRENT_USER\Software\WinRAR SFX
%System Root%%%DOCUME~1%{user name}%LOCALS~1%Temp = "%User Temp%"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
rpcproc.exe = "%User Profile%\Application Data\Microsoft\Media Player\DRM10\rpcproc.exe"

HKEY_CURRENT_USER\Software\WinRAR SFX
%System Root%%%Documents and Settings%{user name}%Application Data%Microsoft%Media Player%DRM10 = "%User Profile%\Application Data\Microsoft\Media Player\DRM10"

Dropping Routine

This Trojan drops the following files:

  • %User Profile%\Application Data\Microsoft\Media Player\DRM10\index.dat
  • %User Profile%\Application Data\Microsoft\Media Player\DRM10\rpcproc.exe
  • %User Profile%\Application Data\Microsoft\Media Player\DRM10\update.dat
  • %User Temp%\ctfmon.exe
  • %User Temp%\javawvd.exe
  • %User Temp%\rstimgr.dll
  • %User Temp%\rstimgr.inf
  • %User Temp%\smcnmgr.exe
  • %User Temp%\system.drv

(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.. %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.)

  SOLUTION

Minimum Scan Engine:

8.900

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

Restart in Safe Mode

[ Learn More ]

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\Microsoft\Windows\CurrentVersion\Run
    • rpcproc.exe = %User Profile%\Application Data\Microsoft\Media Player\DRM10\rpcproc.exe
  • In HKEY_CURRENT_USER\Software\WinRAR SFX
    • %System Root%%%Documents and Settings%{user name}%Application Data%Microsoft%Media Player%DRM10 = %User Profile%\Application Data\Microsoft\Media Player\DRM10
  • In HKEY_CURRENT_USER\Software\WinRAR SFX
    • %System Root%%%DOCUME~1%{user name}%LOCALS~1%Temp = %User Temp%

Step 4

Search and delete this file

[ 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 Profile%\Application Data\Microsoft\Media Player\DRM10\index.dat
%User Profile%\Application Data\Microsoft\Media Player\DRM10\rpcproc.exe
%User Profile%\Application Data\Microsoft\Media Player\DRM10\update.dat
%User Temp%\ctfmon.exe
%User Temp%\javawvd.exe
%User Temp%\rstimgr.dll
%User Temp%\rstimgr.inf
%User Temp%\smcnmgr.exe
%User Temp%\system.drv

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_AGENT.HSC. 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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