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WORM_VBNA.BH

October 09, 2012
 Analysis by: Erika Bianca Mendoza
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW


This worm connects to a server and waits for commands coming from a remote user. Once connected, it may perform various routines.

This worm arrives by connecting affected removable drives to a system. It may be unknowingly downloaded by a user while visiting malicious websites.

It drops copies of itself in all removable drives. 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:

94,208 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

10 May 2011

Arrival Details

This worm arrives by connecting affected removable drives to a system.

It may be unknowingly downloaded by a user while visiting malicious websites.

Installation

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

  • %System%\drivers\{malware name}.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.)

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\policies\
Explorer\Run
Microsoft Driver Setup = "%system%\drivers\{malware name}.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Microsoft Driver Setup = "%system%\drivers\{malware name}.exe"

Propagation

This worm creates the following folders in all removable drives:

  • RECYCLER

It drops copies of itself in all removable drives.

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

NOTES:
This worm connects to a server and waits for commands coming from a remote user. Once connected, it may perform various routines such as:

  • Propagate via USB
  • Port scanning
  • Scan/kill threads
  • Download a file
  • Update itself
  • Create a process

  SOLUTION

Minimum Scan Engine:

8.900

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

Terminate the malware/grayware/spyware process:

[ Learn More ]
  • For Windows 98 and ME users, Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  • If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  • If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

    • 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\policies\Explorer\Run
      • Microsoft Driver Setup = %system%\drivers\{malware name}.exe
    • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
      • Microsoft Driver Setup = %system%\drivers\{malware name}.exe

    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. {Removable drive}\autorun.inf

    Step 5

    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. [removable drive]\RECYCLER

    Step 6

    Scan your computer with your Trend Micro product to delete files detected as WORM_VBNA.BH. 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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