Analysis by: Al Victor de Leon

ALIASES:

Worm:VBS/Slogod.Y (Microsoft), VBS/Autorun.worm.k (Nai), VBS/AutoRun.HG worm (NOD32)

 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:
 INFORMATION EXPOSURE:

  • 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.

It adds certain registry entries to disable the Task Manager. This action prevents users from terminating the malware process, which can usually be done via the Task Manager. It modifies certain registry entries to hide file extensions.

It drops copies of itself in all removable and physical drives found in the system.

  TECHNICAL DETAILS

File Size: 16,064 bytes
File Type: VBS
Memory Resident: Yes
Initial Samples Received Date: 30 May 2014

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 drops the following copies of itself into the affected system and executes them:

  • %Windows%\G4br13l.vbs

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

It drops the following files:

  • %Windows%\boot.ini

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

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
winboot = "wscript.exe /E:vbs %Windows%\boot.ini"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
G4br13l = "%Windows%\.G4br13l.dll.vbs"

Other System Modifications

This worm adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options
attrib.exe =

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
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
TaskMgr.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
setup.exe =

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoDriveTypeAutoRun = 0

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoFileAssociate = 1

(Note: The default value data of the said registry entry is "0".)

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

(Note: The default value data of the said registry entry is "0".)

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

(Note: The default value data of the said registry entry is "0".)

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\Installer
DisableMSI = 1

(Note: The default value data of the said registry entry is "0".)

HKEY_CLASSES_ROOT\Vbsfile\Shell\
Edit\Command
(Default) = "logoff.exe"

(Note: The default value data of the said registry entry is "%System%\Notepad.exe %1".)

HKEY_CLASSES_ROOT\regfile\shell\
open\command
(Default) = "logoff.exe"

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

HKEY_CLASSES_ROOT\inffile\shell\
Install\command
(Default) = "logoff.exe"

(Note: The default value data of the said registry entry is %System%\rundll32.exe setupapi,InstallHinfSection DefaultInstall 132 %1.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
attrib.exe
Debugger = "Notepad.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
cmd.exe
Debugger = "Notepad.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
msconfig.exe
Debugger = "Notepad.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
regedit.exe
Debugger = "Notepad.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
regedt32.exe
Debugger = "Notepad.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
TaskMgr.exe
Debugger = "Notepad.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
install.exe
Debugger = "Notepad.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
setup.exe
Debugger = "Notepad.exe"

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

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Window Title = "HACKED BY AUREL 666"

It adds the following registry entries to disable the Task Manager:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
DisableTaskMgr = 1

(Note: The default value data of the said registry entry is "0".)

It modifies the following registry entries to hide files with Hidden attributes:

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

(Note: The default value data of the said registry entry is "0".)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = 0

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

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

(Note: The default value data of the said registry entry is "0".)

It modifies the following registry entries to hide file extensions:

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

(Note: The default value data of the said registry entry is "0".)

Propagation

This worm drops copies of itself in all removable and physical drives found in the system.

It drops copies of itself in the following drives:

  • {Drive letter}:\autorun.inf
  • {Drive letter}:\G4br13l.vbs

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 10.686.03
FIRST VSAPI PATTERN DATE: 25 Mar 2014
VSAPI OPR PATTERN File: 10.687.00
VSAPI OPR PATTERN Date: 25 Mar 2014

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

Enable Registry Editor

[ Learn More ]
By doing this step, you also enable other applications/programs disabled by this malware/grayware/spyware.

Step 4

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
    • G4br13l = "%Windows%\.G4br13l.dll.vbs"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • winboot = "wscript.exe /E:vbs %Windows%\boot.ini"

Step 5

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: SuperHidden = "1"
      To: SuperHidden = "0"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: ShowSuperHidden = "0"
      To: ShowSuperHidden = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: Hidden = "1"
      To: Hidden = "0"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: HideFileExt = "1"
      To: HideFileExt = "0"
  • In HKEY_CLASSES_ROOT\Vbsfile\Shell\Edit\Command
    • From: (Default) = "logoff.exe"
      To: (Default) = "%System%\Notepad.exe %1"
  • In HKEY_CLASSES_ROOT\regfile\shell\open\command
    • From: (Default) = "logoff.exe"
      To: (Default) = regedit.exe "%1"
  • In HKEY_CLASSES_ROOT\inffile\shell\Install\command
    • From: (Default) = "logoff.exe"
      To: (Default) = %System%\rundll32.exe setupapi,InstallHinfSection DefaultInstall 132 %1

Step 6

Search and delete these files

[ 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.
  • %Windows%\boot.ini
  • {Drive letter}:\autorun.inf
  • {Drive letter}:\G4br13l.vbs

Step 7

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