TROJ_AGENT.MVC

Malware type: Trojan

Aliases: Trojan.Win32.Agent.aqo (Kaspersky), Generic.dx (McAfee), Trojan Horse (Symantec), TR/Agent.aqo.57 (Avira), Troj/Sumkil-A (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: 

This Trojan arrives as a file dropped by other malware. It can also be downloaded unknowingly by a user when visiting malicious Web sites.

It drops files/components.

It attempts to connect to a certain URL to download possibly malicious files. As a result, routines of the downloaded files may also be executed to the affected system.

For additional information about this threat, see:

Description created: Aug. 1, 2007 9:39:48 PM GMT -0800


TECHNICAL DETAILS


File type: PE

Size of malware: 15,360 Bytes

Initial samples received on: Jul 24, 2007

Compression type: UPX

Payload 1: Drops files

Details:

This Trojan arrives as a file dropped by other malware. It can also be downloaded unknowingly by a user when visiting malicious Web sites.

It drops the following files/components:

  • %System%\tracert.dll - also detected by Trend Micro as TROJ_AGENT.MVC
  • %Windows%\vmmreg32.exe - copy of itself

(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. %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

The said DLL component file is then injected into certain running processes.

This Trojan creates the following registry entry to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\
CurrentVersion\Run
Epsilon Squared = "%Windows%\vmmreg32.exe"

It also modifies the following registry entry as part of its installation routine:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Windows
AppInit_DLLs = "tracert.dll"

(Note: The default value data for the said registry entry is blank.)

This Trojan attempts to connect to the following URL to download possibly malicious files:

  • www.{BLOCKED}black.com
  • As a result, routines of the downloaded files may also be executed to the affected system.

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


SOLUTION


Minimum scan engine version needed: 8.000

Pattern file needed: 4.616.07

Pattern release date: Jul 25, 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:

Terminating the Malware Process

This procedure terminates the running malware process.

  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 process:
    vmmreg32.exe
  3. Select the malware process, then press either the End Task or the End Process button, depending on the version of Windows on your computer.
  4. To check if the malware process has been terminated, close Task Manager, and then open it again.
  5. 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.

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. 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.

Restarting in Safe Mode

This malware has characteristics that require the computer to be restarted in safe mode. Go to this page for instructions on how to restart your computer in safe mode.

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).

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:
    %System%\tracert.dll
    (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.)
  3. In the Look In drop-down list, select My Computer, then press Enter.
  4. Once located, select the file then press SHIFT%20DELETE.
  5. Repeat steps 2-4 for the the following file:
    %Windows%\vmmreg32.exeM
    (Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

Removing Autostart Entries from the Registry

This solution deletesthe registry entries added by this malware. Before performing the steps below, make sure you know how to back up the registry and how to restore it if a problem occurs. Refer to this Microsoft article for more information about modifying your computer's registry.

  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:
    Epsilon Squared = %WINDOWS%\vmmreg32.exe"

Restoring Other Registry Entries

  1. Still in Registry Editor, in the left panel, double-click the following:
    HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>
    Windows NT>CurrentVersion>Windows
  2. In the right panel, locate the entry:
    AppInit_DLLs = tracert.dll"
  3. Right-click on the value name and choose Modify. Change the value data of this entry to blank.
  4. Close Registry Editor.

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.MVC. To do this, Trend Micro customers must download the latest virus pattern file and scan their computers. Other Internet users can use HouseCall, the Trend Micro online threat scanner.




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