TROJ_REDOSDR.AH

 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: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware


This Trojan sends certain information.

This Trojan may be dropped by other malware.

It connects to certain websites to send and receive information. It opens a hidden Internet Explorer window. It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size:

Varies

File Type:

EXE, DLL

Memory Resident:

Yes

Initial Samples Received Date:

12 Mar 2012

Payload:

Sends information

Arrival Details

This Trojan may be dropped by the following malware:

  • TROJ_ARTIEF.CP

Installation

This Trojan drops the following copies of itself into the affected system:

  • %User Temp%\kbdmgr.exe

(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.)

Its DLL component is injected to the following process(es):

  • IEXPLORE.EXE

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • WuSh B- Is Running!
  • m4qtrsz5bfn3o1g
  • freetibet2012.xicp.net

It terminates the execution of the copy it initially executed and executes the copy it drops instead.

Autostart Technique

This Trojan drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:

  • kbdmgr.lnk

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\kbdmgr.dll - also detected by Trend Micro as TROJ_REDOSDR.AH

(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.)

Other Details

This Trojan connects to the following website to send and receive information:

  • http://{BLOCKED}bet2012.xicp.net:8089/h.gif?pid =113&v=130586214568

It opens a hidden Internet Explorer window.

It deletes the initially executed copy of itself

NOTES:

It sends the following information:

  • Operating system language
  • Operating system version
  • Total physical memory

As of this writing, there is no response from the website.

It sets the hidden attribute of the folder %User Startup%.

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

8.832.04

FIRST VSAPI PATTERN DATE:

12 Mar 2012

VSAPI OPR PATTERN File:

8.833.00

VSAPI OPR PATTERN Date:

13 Mar 2012

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

Remove the malware/grayware file that dropped/downloaded TROJ_REDOSDR.AH

Step 3

Restart in Safe Mode

[ Learn More ]

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 Startup%\kbdmgr.lnk

Step 5

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

NOTES:

To unhide the %User Startup% folder:

  1. Open a Command Prompt window.
    For Windows 2000, Windows XP, and Windows Server 2003 users, click Start>Run. In the Open input box, type CMD then press Enter.
  2. Type the following command:
    ATTRIB -H "User Startup"
  3. Type the command EXIT to close the Command Prompt window.


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