VBS_AUTORUN.LDG

 Analysis by: Adrian Cofreros

 ALIASES:

Worm:VBS/Jenxcus.A(Microsoft),VBS/Agent.NDJ worm(NOD32),VBS/Autorun.DZ(Antivir)

 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

Infection Channel:

Downloaded from the Internet, Dropped by other malware, Propagates via flashdrives

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 listens on ports. It connects to a website to send and receive information.

  TECHNICAL DETAILS

File Size:

Varies

File Type:

VBS

Memory Resident:

Yes

Initial Samples Received Date:

02 Jul 2013

Payload:

Connects to URLs/IPs, Steals information, Drops files

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:

  • %User Temp%\Updatea.vbs

(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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

It drops the following files:

  • {removable drive letter}:\{filename}.lnk - created shortcuts on the same directory.
  • %User Profile%\Recent\{malware folder}.lnk
  • %User Profile%\Recent\{malware name}.vbs.lnk

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

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
Updatea.vbs = "%User Temp%\Updatea.vbs"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Updatea.vbs = "%User Temp%\Updatea.vbs"

It drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:

  • %User Startup%\Updatea.vbs - copy of itself

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.)

Other System Modifications

This worm adds the following registry entries:

HKEY_CURRENT_USER
mared = "{y/n}"

Propagation

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

  • {removable drive letter}:\Updatea.vbs

Backdoor Routine

This worm listens on the following port(s):

  • TCP Port: 7777

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

  • http://{BLOCKED}.{BLOCKED}ounterstrike.com

NOTES:

The data value for registry entry mared depends upon execution:

  • (y)-if run on root directory of any drive
  • (n)-run elsewhere

It gathers the following information from the infected machine:

  • Computer Name
  • User Name
  • Volume Serial Number

It can execute commands from remote malicious users. It also has the ability to restore its infected removable drive.

It modifies the target of all its created shortcuts on the removable drives for it to propagate:

  • %System%\cmd.exe /c start Updatea.vbsstart {file name}.{file extension} exit

It hides files in the removable drive's root directory.

It checks for file infection if detects a similar shortcut on the same directory.

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

10.130.06

FIRST VSAPI PATTERN DATE:

02 Jul 2013

VSAPI OPR PATTERN File:

10.131.00

VSAPI OPR PATTERN Date:

03 Jul 2013

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

Scan your computer with your Trend Micro product and note files detected as VBS_AUTORUN.LDG

Step 3

Restart in Safe Mode

[ Learn More ]

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • Updatea.vbs = "%User Temp%\Updatea.vbs"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Updatea.vbs = "%User Temp%\Updatea.vbs"
  • In HKEY_CURRENT_USER
    • mared = "{y/n}"

Step 5

Search and delete the files detected as VBS_AUTORUN.LDG

*Note: Some component files may be 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.

To stop the malware/grayware from running when certain files are opened:

For Windows 2000, Windows XP, and Windows Server 2003:

  1. Right-click Start then click Search....
  2. In the Named input box, type the name of the file that was detected earlier.
  3. In the Look In drop-down list, select My Computer then press Enter.
  4. Once located, select the file then press SHIFT+DELETE to delete it.

For Windows Vista and Windows 7:

  1. Click Start>Computer.
  2. In the Search Computer input box, type the name of the file detected earlier, and press Enter.
  3. Once located, select the file then press SHIFT+DELETE to delete it.
    *Note: Read the following Microsoft page if these steps do not work on Windows 7.

Step 6

Search and delete these files

[ Learn More ]
There may be some 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.

Step 7

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