Analysis by: Cris Nowell Pantanilla
 PLATFORM:

Windows 98, ME, NT, 2000, XP, Server 2003

 OVERALL RISK RATING:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan may be downloaded by other malware/grayware/spyware from remote sites. It may be unknowingly downloaded by a user while visiting malicious websites.

  TECHNICAL DETAILS

File Size: 28,000 bytes
File Type: EXE
Memory Resident: Yes

Arrival Details

This Trojan may be downloaded by other malware/grayware/spyware from remote sites.

It may be unknowingly downloaded by a user while visiting malicious websites.

Installation

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

  • %WINDOWS%\Fonts\{random}\system\1111.exe

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

  • _!MSFTHISTORY!_

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\
CurrentVersion\Run
TBMExe = Windows%\Fonts\{Random}\system\1111.exe

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\
CurrentVersion\Image File Execution Options\

{Application Name}
Debugger = c:\MMM.exe

HKEY_LOCAL_MACHINE\SOFTWARE\GoogleBA
(Default) =

HKEY_CURRENT_USER\Control Panel\Cursors
AppStarting = {blank}

HKEY_CURRENT_USER\Control Panel\Cursors
Arrow = {blank}

Dropping Routine

This Trojan drops the following files:

  • %WINDOWS%\Fonts\{random}\system\KB930.vxd

Download Routine

This Trojan accesses the following websites to download files:

  • http://{BLOCKED}05916.com
  • http://{BLOCKED}83216.com
  • http://{BLOCKED}987255.com/logo.gif
  • http://www.{BLOCKED}union.com/

  SOLUTION

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\ CurrentVersion\Run
    • TBMExe = Windows%\Fonts\{Random}\system\1111.exe
  • In HKEY_CURRENT_USER\Control Panel\Cursors
    • AppStarting =
      Arrow =

Step 3

Delete this registry key

[ 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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options
    • {Application Name}
  • In HKEY_LOCAL_MACHINE\SOFTWARE
    • GoogleBA

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_KILLAV.RX. 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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