Modified by: Alvin Bacani
ALIASES:

Worm:Win32/VB.UK (Microsoft); Generic VB.b (McAfee); W32.Botou (Symantec); Worm.Win32.VB.act, Worm.Win32.VB.act (Kaspersky); Trojan.VB.Agent.FT (FSecure)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  TECHNICAL DETAILS

File Size: 32,768 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 24 Apr 2012

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:

  • "%System%\FUvirus.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

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
FU = "%System%\FUvirus.exe"

Other System Modifications

This worm adds the following registry entries:

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

Propagation

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

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 6.330.05
FIRST VSAPI PATTERN DATE: 30 Jul 2009
VSAPI OPR PATTERN File: 6.331.00
VSAPI OPR PATTERN Date: 30 Jul 2009

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 WORM_VB.WTRY

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Search and delete files detected as WORM_VB.WTRY

[ 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.

Step 5

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
    • FU = %System%\FUvirus.exe
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • ShowSuperHidden = 0

Step 6

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