VBS_SOLOW.A

 Analysis by: Rhena Inocencio

 ALIASES:

Worm.VBS.Solow.b (Kaspersky), VBS/IE-Title (McAfee), VBS.Solow (Symantec), VBS/Solow.B (Avira), VBS/Sasan-Fam (Sophos)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

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

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

  TECHNICAL DETAILS

File Size:

Varies

File Type:

VBS

Initial Samples Received Date:

30 Jan 2007

Arrival Details

This worm arrives via removable drives.

It 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 drops the following copies of itself into the affected system:

  • %Windows%\{Random}.DLL.VBS
  • %System Root%\{Random}.DLL.VBS

(Note: %Windows% is the Windows folder, which is usually C:\Windows.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

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\Run
{random name} = "%Windows%\{Random}.dll.vbs"

Other System Modifications

This worm adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoFind = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoRun = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoFolderOptions = "1"

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

It adds the following registry entries as part of its installation routine:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Window Title = "Hacked by Godzilla"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Window Title = "Hacked by MOOzilla"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Window Title = "Hacked by UC"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Window Title = "Hacked by YaHaa, Your Firewall Is FUCK."

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Window Title = "Malaysian Hackers"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Window Title = "Protected by CPCT"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Window Title = "TAGA ETI, MARINDUQUE MABUHAY!!! by: Nicklaus S. Buag"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Window Title = "TAGA LIPA ARE!"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Window Title = "TAGA XPRESS-ON KAMI"

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "0"

(Note: The default value data of the said registry entry is user-defined.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion
RegisteredOrganization = "{Random}"

(Note: The default value data of the said registry entry is user-defined.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion
RegisteredOwner = "{Random}"

(Note: The default value data of the said registry entry is user-defined.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion
ProductId = "{Random}"

(Note: The default value data of the said registry entry is user-defined.)

HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\
System\CentralProcessor\0
ProcessorNameString = "{Random}"

(Note: The default value data of the said registry entry is user-defined.)

Propagation

This worm drops the following copy(ies) of itself in all removable drives:

  • {drive letter}:\{Random}.DLL.VBS

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

The said .INF file contains the following strings:

[AutoRun]
shellexecute=wscript.exe {Random}.dll.vbs

Other Details

This worm requires the existence of the following files to properly run:

  • wscript.exe

NOTES:

It creates registry entries that changes the text displayed in the title bar of Internet Explorer.

It adds the registry entry Debugger = "notepad.exe" in the following registry keys:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\cmd.exe
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\install.exe
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\msconfig.exe
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\regedit.exe
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\regedt32.exe
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\RegistryEditor.exe
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\setup.exe

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

4.238.03

FIRST VSAPI PATTERN DATE:

01 Feb 2007

VSAPI OPR PATTERN File:

4.239.00

VSAPI OPR PATTERN Date:

02 Feb 2007

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Restart in Safe Mode

[ 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\Run
    • {random name} = "%Windows%\{Random}.dll.vbs
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • Window Title = "Hacked by Godzilla"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • Window Title = "Hacked by MOOzilla"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • Window Title = "Hacked by UC"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • Window Title = "Hacked by YaHaa, Your Firewall Is FUCK."
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • Window Title = "Hacked by Zay"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • Window Title = "Malaysian Hackers"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • Window Title = "Protected by CPCT"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • Window Title = "TAGA ETI, MARINDUQUE MABUHAY!!! by: Nicklaus S. Buag"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • Window Title = "TAGA LIPA ARE!"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • Window Title = "TAGA XPRESS-ON KAMI"
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\cmd.exe
    • Debugger = "notepad.exe"
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\install.exe
    • Debugger = "notepad.exe"
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\msconfig.exe
    • Debugger = "notepad.exe"
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\regedit.exe
    • Debugger = "notepad.exe"
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\regedt32.exe
    • Debugger = "notepad.exe"
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\RegistryEditor.exe
    • Debugger = "notepad.exe"
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\setup.exe
    • Debugger = "notepad.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
    • NoFind = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
    • NoRun = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
    • NoFolderOptions = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
    • DisableRegistryTools = "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: Hidden = "0"
      To: Hidden = "{user-defined}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion
    • From: RegisteredOrganization = "{Random}"
      To: RegisteredOrganization = "{user-defined}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion
    • From: RegisteredOwner = "{Random}"
      To: RegisteredOwner = "{user-defined}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion
    • From: ProductId = "{Random}"
      To: ProductId = "{user-defined}"
  • In HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\0
    • From: ProcessorNameString = "{Random}"
      To: ProcessorNameString = "{user-defined}"

Step 5

Search and delete AUTORUN.INF files created by VBS_SOLOW.A that contain these strings

[ Learn More ]


[AutoRun]
shellexecute=wscript.exe {Random}.dll.vbs

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as VBS_SOLOW.A. 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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