TROJ_TIBS.AI

Malware type: Trojan

Aliases: Email-Worm.Win32.Zhelatin.et (Kaspersky), W32/Zhelatin.gen (McAfee), Trojan.Packed.13 (Symantec), TR/Small.DBY.DB (Avira), Mal/TibsPak (Sophos),

In the wild: Yes

Destructive: No

Language: English

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

Encrypted: No

Overall risk rating:

Reported infections:

Damage potential:

Medium

Distribution potential:

Low

Description: 

To get a one-glance comprehensive view of the behavior of this malware, refer to the Behavior Diagram shown below.

TROJ_TIBS.AI Behavior Diagram

Malware Overview

This Trojan arrives on a system as a file dropped by CHM_CODEBASE.BS, or downloaded by TROJ_ANIMOO.D. Users are strongly advised to also remove the mentioned related malware in order to prevent the system from being re-infected by this Trojan.

It may also be downloaded by users from the malicious Web site http://traf{BLOCKED}ll.biz/adv/064/win32.exe.

Upon execution, it drops a copy of itself as KERNELS8.EXE in the Windows system folder.

It modifies the registry to disable the Windows Task Manager. The said routine prevents affected users from easily detecting its running process which, consequently, makes it more difficult to remove.

This Trojan accesses specific Web sites to download possibly malicious files, thus increasing the risk of the affected system.

For additional information about this threat, see:

Description created: May. 23, 2006 5:02:26 PM GMT -0800


TECHNICAL DETAILS


File type: PE

Memory resident:  Yes

Size of malware: 8,171 Bytes (compressed)

Initial samples received on: May 23, 2006

Compression type: Upolyx

Related toCHM_CODEBASE.BS, TROJ_ANIMOO.D

Payload 1: Downloads files

Payload 2: Disables Windows Task Manager

Details:

Installation and Autostart Technique

This Trojan arrives on a system as a file dropped by CHM_CODEBASE.BS, or downloaded by TROJ_ANIMOO.D. Users are strongly advised to also remove the mentioned related malware in order to prevent the system from being re-infected by this Trojan.

It may also be downloaded by users from the malicious Web site http://traf{BLOCKED}ll.biz/adv/064/win32.exe.

Upon execution, it drops a copy of itself as KERNELS8.EXE in the Windows system folder.

It creates the following registry entry to ensure its automatic execution at every Windows startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
System = "%System%\kernels8.exe"

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It also creates the following registry entry to disable the Windows Task Manager:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\System
DisableTaskMgr = "dword:00000001"

It modifies the registry to disable the Windows Task Manager. The said routine prevents affected users from easily detecting its running process which, consequently, makes it more difficult to remove.

Download Routine

This Trojan accesses specific Web sites to download possibly malicious files in the Windows system folder, as follows:

The following are the Web sites it accesses:

Other Details

This Trojan runs on Windows 98, ME, NT, 2000, XP, and Server 2003.

Analysis By: Jason Pantig

Revision History:

First pattern file version: 4.527.00
First pattern file release date: Jun 11, 2007

SOLUTION


Minimum scan engine version needed: 7.500

Pattern file needed: 5.605.00

Pattern release date: Oct 16, 2008


Important note: The "Minimum scan engine" refers to the earliest Trend Micro scan engine version guaranteed to detect this threat. However, Trend Micro strongly recommends that you update to the latest version in order to get comprehensive protection. Download the latest scan engine here.

Solution:

Note: To fully remove all associated malware, perform the clean solutions for the following:

Terminating the Malware Program

Since this malware terminates the Windows Task Manager, it is necessary to use third party process viewers such as Process Explorer.

If the process you are looking for is not in the list displayed by Process Explorer, proceed to the succeeding solution set.

  1. Download Process Explorer.
  2. Extract the contents of the compressed (ZIP) file to a location of your choice.
  3. Execute Process Explorer by double-clicking procexp.exe.
  4. In the Process Explorer window, locate the process:
    KERNELS8.EXE
  5. Right-click the malware process, then click Kill Process Tree.
  6. Close Process Explorer.

*NOTE: On computers running all Windows platforms, if the process you are looking for is not in the list displayed by Process Explorer, continue with the next solution procedure, noting additional instructions. If the malware process is in the list displayed by Process Explorer, but you are unable to terminate it, restart your computer in safe mode.

Editing the Registry

This malware modifies the computer's registry. Users affected by this malware may need to modify or delete specific registry keys or entries. For detailed information regarding registry editing, please refer to the following articles from Microsoft:

  1. HOW TO: Backup, Edit, and Restore the Registry in Windows 95, Windows 98, and Windows ME
  2. HOW TO: Backup, Edit, and Restore the Registry in Windows NT 4.0
  3. HOW TO: Backup, Edit, and Restore the Registry in Windows 2000
  4. HOW TO: Back Up, Edit, and Restore the Registry in Windows XP and Server 2003

Removing Autostart Entries from the Registry

Removing autostart entries from the registry prevents the malware from executing at startup.

If the registry entries below are not found, the malware may not have executed as of detection. If so, proceed to the succeeding solution set.

  1. Open Registry Editor. Click Start>Run, type REGEDIT, then press Enter.
  2. In the left panel, double-click the following:
    HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>
    Windows>CurrentVersion>Run
  3. In the right panel, locate and delete the entry:
    System = "%System%\kernels8.exe"
    (Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, and C:\Windows\System32 on Windows XP and Server 2003.)

Removing Added Entry in the Registry

  1. Still in Registry Editor, in the left panel, double-click the following:
    HKEY_CURRENT_USER>Software>Microsoft>
    Windows>CurrentVersion>Policies>System
  2. In the right panel, locate and delete the entry:
    DisableTaskMgr = "dword:00000001"
  3. Close Registry Editor.

Important Windows ME/XP Cleaning Instructions

Users running Windows ME and XP must disable System Restore to allow full scanning of infected computers.

Users running other Windows versions can proceed with the succeeding solution set(s).

Running Trend Micro Antivirus

If you are currently running in safe mode, please restart your computer normally before performing the following solution.

Scan your computer with Trend Micro antivirus and delete files detected as TROJ_TIBS.AI. To do this, Trend Micro customers must download the latest virus pattern file and scan their computer. Other Internet users can use HouseCall, the Trend Micro online virus scanner.




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