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TROJ_BHO.KJ

October 09, 2012
 Analysis by: Michael Cabel
 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


This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size:

157,184 bytes

File Type:

DLL

Memory Resident:

Yes

Initial Samples Received Date:

06 Aug 2007

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Autostart Technique

This Trojan registers itself as a BHO to ensure its automatic execution every time Internet Explorer is used by adding the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects\{4E8D6551-F9A4-6D01-4D4B-BFD7673C0E3E}

Other System Modifications

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

HKEY_CLASSES_ROOT\MoreRelevantAdvertisingProgram.MoreRelevantAdvertisingProgram

HKEY_CLASSES_ROOT\MoreRelevantAdvertisingProgram.MoreRelevantAdvertisingProgram.1

HKEY_CLASSES_ROOT\AppID\MoreRelevantAdvertisingProgram.DLL

HKEY_CLASSES_ROOT\AppID\{418D86BE-7386-4F1A-83E0-53604ADBDA74}

HKEY_CLASSES_ROOT\CLSID\{4E8D6551-F9A4-6D01-4D4B-BFD7673C0E3E}

HKEY_CLASSES_ROOT\Interface\{74227A16-0FA2-0406-D0AB-28B158DFD4C5}

HKEY_CLASSES_ROOT\TypeLib\{DDBF94DA-A3F9-A0A0-B916-33351799AD17}

  SOLUTION

Minimum Scan Engine:

8.900

FIRST VSAPI PATTERN FILE:

4.636.02

FIRST VSAPI PATTERN DATE:

06 Aug 2007

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

Scan your computer with your Trend Micro product and note files detected as TROJ_BHO.KJ

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Search and delete the file detected as TROJ_BHO.KJ

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files in the search result.

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_BHO.KJ. 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 remove BHO Keys:

  1. Close all instances of opened Internet browser windows.
    Open a command prompt window. Click Start>Run.
      On Windows 98 and ME, type

    COMMAND, then press Enter.
    On Windows NT, 2000, XP, and Server 2003, type
    CMD, then press Enter.
  2. In the command prompt, type the following, then press Enter:
    CD {Malware Path}
  3. Still in the command prompt type the following then press Enter:
    On Windows 98 and ME, type
    RUNDLL {Malware File Name},DllUnregisterServer
    On Windows NT, 2000, XP, and Server 2003, type
    REGSVR32 {Malware File Name} /U
  4. Click Yes or OK when prompted.
  5. Close command prompt.


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