M December 12, 2008 Virus Alert - WORM_AUTORUN.UP
WORM_AUTORUN.UP
   
Virus type: Worm
Destructive:  No
Aliases: Worm.Win32.AutoRun.dgl (Kaspersky), W32/Autorun.worm.bm (McAfee), Worm/Autorun.dgl.2 (Avira), Mal/Generic-A (Sophos),
Pattern file needed: 5.688.05
Scan engine needed: 8.500
Overall risk rating: Low
Reported infections: Low
Damage Potential: Medium
Distribution Potential: High

Description :

This worm may be dropped by other malware. It may be downloaded unknowingly by a user when visiting malicious Web sites. It may also arrive via removable drives.

Upon execution, this worm drops several copies of itself. This worm modifies a registry entry to enable its automatic execution at every system startup.

This worm drops copies of itself in all removable drives. It also drops an AUTORUN.INF file to automatically execute its dropped copies when the said drives are accessed.

It also connects to a certain URL to download a copy of itself.

Solution :

Identifying the Malware Files

  1. Scan your computer with your Trend Micro antivirus product.
  2. Note the path and file name of all files detected as WORM_AUTORUN.UP.

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

Terminating the Malware Program

Since this malware uses a file name that is also the file name of a legitimate process, it is necessary to use third party process viewers such as Process Explorer to isolate the malware process itself. You will need the name(s) of the file(s) detected earlier.

  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:
    userinit.exe
  5. Right-click the malware process, and choose Properties.
  6. Check if the value for the Current Directory is the following:
    %Windows%
    (Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)
  7. If yes, then right-click on the malware process, and click Kill Process Tree.
  8. 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.

Removing Autostart Entries from the Registry

This solution deletes/modifies registry keys/entries added/modified 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 NT> CurrentVersion>Winlogon
  3. In the right panel, locate the entry:
    Userinit = "%Windows%\userinit.exe"
    (Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)
  4. Right-click on the value name and choose Modify. Change the value data of this entry to:
    "%System%\userinit.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.)
  5. 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:
    %Windows%\kdcoms32.dll
  3. In the Look In drop-down list, select the drive that contains Windows, then press Enter.
  4. Once located, select the file then press SHIFT+DELETE.
  5. Repeat steps 2-4 for the following file(s):
    %Windows%\kdcoms.dll

Deleting Malware-created AUTORUN.INF/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:
    AUTORUN.INF
  3. In the Look In drop-down list, select a removable drive, then press Enter.
  4. Select the file, then open using Notepad.
  5. Check if the following lines are present in the file:
    [AUTORUN]
    Shellexecute=Secret.exe
  6. If the lines are present, delete the file.
  7. Repeat steps 3 to 6 for AUTORUN.INF files in the remaining removable drives.
  8. Close Search Results.

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

Scan your computer with Trend Micro antivirus and delete files detected as WORM_AUTORUN.UP. 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.

Trend Micro offers best-of-breed antivirus and content-security solutions for your corporate network or home PC.


For additional information about this threat, see Technical Details.