WORM_VB.ECU


 ALIASES:

Microsoft: Worm:Win32/Agent; Kaspersky: P2P-Worm.Win32.VB.sv

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

It is capable of propagating via P2P shares.

This worm connects to a website to send and receive information.

  TECHNICAL DETAILS

File Size:

793,693 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

26 Jan 2011

Installation

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

  • %System%\Windupdt\winupdate.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 drops the following non-malicious file:

  • %User Temp%\_dcsc_.bat

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.)

It creates the following folders:

  • %System%\Windupdt

(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.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
winupdater = %System%\Windupdt\winupdate.exe

It modifies the following registry entry(ies) to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = C:\WINDOWS\system32\userinit.exe,%System%\Windupdt\winupdate.exe

(Note: The default value data of the said registry entry is C:\WINDOWS\system32\userinit.exe,.)

Other System Modifications

This worm adds the following registry keys:

HKEY_CURRENT_USER\Software\DC3_FEXEC

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableRegistryTools = 1

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
EnableLUA = 0

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusDisableNotify = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
UpdatesDisableNotify = 1

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
EnableFirewall = 1

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DisableNotifications = 1

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\wscsvc
Start = 4

(Note: The default value data of the said registry entry is 2.)

Backdoor Routine

This worm opens the following ports:

  • 1604

It connects to the following websites to send and receive information:

  • {BLOCKED}.{BLOCKED}5.150.130 - inaccessible as of writing

Other Details

Based on analysis of the codes, it has the following capabilities:

  • It is capable of propagating via P2P shares.

  SOLUTION

Minimum Scan Engine:

8.900

VSAPI OPR PATTERN File:

7.795.00

VSAPI OPR PATTERN Date:

26 Jan 2011

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Identify and delete files detected as WORM_VB.ECU using either the Startup Disk or Recovery Console

[ Learn More ]

Step 3

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.  %System%\Windupdt

Step 4

Search and delete this file

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files and folders in the search result. %User Temp%\_dcsc_.bat

Step 5

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_CURRENT_USER\Software
    • DC3_FEXEC

Step 6

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
    • DisableRegistryTools = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
    • EnableLUA = 0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • AntiVirusDisableNotify = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • UpdatesDisableNotify = 1
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
    • EnableFirewall = 1
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
    • DisableNotifications = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • winupdater = %System%\Windupdt\winupdate.exe

Step 7

Restore this modified 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 NT\CurrentVersion\Winlogon
    • From: Userinit = C:\WINDOWS\system32\userinit.exe,%System%\Windupdt\winupdate.exe
      To: Userinit = C:\WINDOWS\system32\userinit.exe,
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\wscsvc
    • From: Start = 4
      To: Start = 2

Step 8

Scan your computer with your Trend Micro product to delete files detected as WORM_VB.ECU. 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.


Did this description help? Tell us how we did.