TROJ_AGENT.JVH

Malware type: Trojan

Aliases: Email-Worm.Win32.Zhelatin.ah (Kaspersky), Downloader-BAI.gen.d (McAfee), Trojan.Packed.13 (Symantec), TR/Small.DBY.AM (Avira), Mal/EncPk-E (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: 

Barely three weeks into the new year, as the storm "Kyrill" ravaged over central Europe, another "storm" brewed. The new storm was a deluge of spam email messages that promised to bring information about Europe's most severe winter storm since 1999, with subject lines such as "230 dead as storm batters Europe", among others.

That is how this Trojan, arriving as attachment to the said email messages, came to be dubbed the "Storm" malware. But this Trojan is more than just a malware with a clever social engineering technique. Tagging WORM_NUWAR.CQ along, it created a partnership that staged a complex attack.

To read a comprehensive article about the routines and ultimate goals of the TROJ_SMALL.EDW-WORM_NUWAR.CQ tandem, click here: TROJ_SMALL.EDW Storms into Inboxes, Teams Up with NUWAR to Create Unique Network.

This Trojan usually arrives on a system as the file GAME0.EXE, which is downloaded by TROJ_SMALL.EDW.

Upon execution, it drops a copy of itself in the Windows system directory. It also drops a file, detected by Trend Micro as TROJ_ROOTKIT.CL, in the same folder.

It sends information about an affected system, as well as downloads an updated copy of itself, from certain Web sites.

It sends an acknowledgement to a certain Web site upon successful execution of the information theft and download routines.

For additional information about this threat, see:

Description created: Jan. 23, 2007 5:46:47 AM GMT -0800


TECHNICAL DETAILS


File type: PE

Memory resident:  Yes

Size of malware: 54,403 Bytes

Initial samples received on: Jan 21, 2007

Related toTROJ_SMALL.EDW, TROJ_ROOTKIT.CL

Payload 1: Downloads files

Payload 2: Steals information

Payload 3: Sends acknowledgement of routines to a Web site

Details:

Installation and Autostart Technique

This Trojan usually arrives on a system as the file GAME0.EXE, which is downloaded by TROJ_SMALL.EDW.

Upon execution, it drops the following files in the Windows system directory:

  • taskdir.exe - copy of itself
  • adir.dll - detected by Trend Micro as TROJ_ROOTKIT.CL
  • zlbw.dll - non-malicious .DLL file

It creates the following registry entry to enable its automatic execution at every sytem startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\
CurrentVersion\Run
taskdir = "%System%\taskdir.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.)

Information Theft

This Trojan sends information about an affected system, such as computer names, to the following Web sites:

  • http://69.{BLOCKED}.166.234/cp/rule.php
  • http://81.{BLOCKED}.26.27/cp/rule.php
  • http://205.{BLOCKED}.179.112/cp/rule.php
  • http://209.{BLOCKED}.8.198/cp/rule.php
  • http://217.{BLOCKED}.217.187/cp/rule.php

Download Routine

This Trojan connects to the Web site http://81.{BLOCKED}.26.20/cp/bin/lim to download an updated copy of itself.

Other Details

This Trojan sends an acknowledgement to the Web site http://217.{BLOCKED}.217.187/sp/post.php upon successful execution of the information theft and download routines.

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

Analysis By: Lennard Galang

Revision History:

First pattern file version: 4.202.01
First pattern file release date: Jan 21, 2007

SOLUTION


Minimum scan engine version needed: 8.000

Pattern file needed: 4.291.00

Pattern release date: Feb 22, 2007


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:

Identifying the Malware Program

To remove this malware, first identify the malware program.

  1. Scan your computer with your Trend Micro antivirus product.
  2. NOTE the path and file name of all files detected as TROJ_AGENT.JVH.

Trend Micro customers need to download the latest virus pattern file before scanning their computer. Other users can use Housecall, the Trend Micro online virus scanner.

Terminating the Malware Program

This procedure terminates the running malware process. You will need the name(s) of the file(s) detected earlier.

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

  1. Open Windows Task Manager.
    • On Windows 98 and ME, press
    CTRL%20ALT%20DELETE
    • On Windows NT, 2000, XP, and Server 2003, press
    CTRL%20SHIFT%20ESC, then click the Processes tab.
  2. In the list of running programs*, locate the malware file(s) detected earlier.
  3. Select one of the detected files, then press either the End Task or the End Process button, depending on the version of Windows on your computer.
  4. Do the same for all detected malware files in the list of running processes.
  5. To check if the malware process has been terminated, close Task Manager, and then open it again.
  6. Close Task Manager.

*NOTE: On computers running Windows 98 and ME, Windows Task Manager may not show certain processes. You can use a third party process viewer such as Process Explorer to terminate the malware process.

On computers running all Windows platforms, if the process you are looking for is not in the list displayed by Task Manager or Process Explorer, continue with the next solution procedure, noting additional instructions. If the malware process is in the list displayed by either Task Manager or 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 entry below is 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:
    taskdir = �%System%\taskdir.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.)
  4. Close Registry Editor.

Deleting the Malware File(s)

  1. Right-click Start then click Search... or Find..., depending on the version of Windows you are running.
  2. In the Named input box, type:
    zlbw.dll
  3. In the Look In drop-down list, select drive that contains Windows, then press Enter.
  4. Once located, select the file then press SHIFT%20DELETE.

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_AGENT.JVH. 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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