WORM_VB.GLA


 ALIASES:

Worm:Win32/Pahati.A (Microsoft); New Malware.d !! (McAfee); W32.SillyDC (Symantec); Virus.Win32.VB.ef, Virus.Win32.VB.ef (Kaspersky); Trojan.Win32.Generic.pak!cobra (Sunbelt); Win32.Worm.VB.NUK (FSecure)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW


This worm arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size:

53,248 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

03 Nov 2011

Arrival Details

This worm arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This worm creates the following folders:

  • %Program Files%\Microsoft Office\

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunOnce
(Default) = "%System Root%\System Volume Information\WORD32.EXE"

It modifies the following registry entries to ensure it automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
shell = "explorer.exe, %Program Files%\Microsoft Office\WINWORD.EXE"

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

Other System Modifications

This worm adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ClassicViewState = 1

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
HideFileExt = 1

(Note: The default value data of the said registry entry is 1.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\advapi32.dll[MofResourceName] = "LowDateTime:-878345984,HighDateTime:29653303***Binary mof compiled successfully"

(Note: The default value data of the said registry entry is LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\DRIVERS\ACPI.sys[ACPIMOFResource] = "LowDateTime:-1893836544,HighDateTime:29653288***Binary mof compiled successfully"

(Note: The default value data of the said registry entry is LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\DRIVERS\mssmbios.sys[MofResource] = "LowDateTime:246686720,HighDateTime:29653305***Binary mof compiled successfully"

(Note: The default value data of the said registry entry is LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\DRIVERS\intelppm.sys[PROCESSORWMI] = "LowDateTime:1716098048,HighDateTime:29653287***Binary mof compiled successfully"

(Note: The default value data of the said registry entry is LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\DRIVERS\ipnat.sys[IPNATMofResource] = "LowDateTime:741130752,HighDateTime:29653288***Binary mof compiled successfully"

(Note: The default value data of the said registry entry is LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\Drivers\HTTP.sys[UlMofResource] = "LowDateTime:-2038869248,HighDateTime:29653287***Binary mof compiled successfully"

(Note: The default value data of the said registry entry is LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.200

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.GLA using either the Startup Disk or Recovery Console

[ Learn More ]

Step 3

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce
    • (Default)="%System Root%\System Volume Information\WORD32.EXE"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • ClassicViewState=1

Step 4

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: HideFileExt=1
      To: HideFileExt=1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
    • From: %System%\advapi32.dll[MofResourceName]="LowDateTime:-878345984,HighDateTime:29653303***Binary mof compiled successfully"
      To: %System%\advapi32.dll[MofResourceName]=LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
    • From: %System%\DRIVERS\ACPI.sys[ACPIMOFResource]="LowDateTime:-1893836544,HighDateTime:29653288***Binary mof compiled successfully"
      To: %System%\DRIVERS\ACPI.sys[ACPIMOFResource]=LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
    • From: %System%\DRIVERS\mssmbios.sys[MofResource]="LowDateTime:246686720,HighDateTime:29653305***Binary mof compiled successfully"
      To: %System%\DRIVERS\mssmbios.sys[MofResource]=LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
    • From: %System%\DRIVERS\intelppm.sys[PROCESSORWMI]="LowDateTime:1716098048,HighDateTime:29653287***Binary mof compiled successfully"
      To: %System%\DRIVERS\intelppm.sys[PROCESSORWMI]=LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
    • From: %System%\DRIVERS\ipnat.sys[IPNATMofResource]="LowDateTime:741130752,HighDateTime:29653288***Binary mof compiled successfully"
      To: %System%\DRIVERS\ipnat.sys[IPNATMofResource]=LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
    • From: %System%\Drivers\HTTP.sys[UlMofResource]="LowDateTime:-2038869248,HighDateTime:29653287***Binary mof compiled successfully"
      To: %System%\Drivers\HTTP.sys[UlMofResource]=LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
    • From: shell="explorer.exe, %Program Files%\Microsoft Office\WINWORD.EXE"
      To: shell=Explorer.exe

Step 5

Search and delete this folder

[ 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. %Program Files%\Microsoft Office\

Step 6

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


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