Analysis by: Kathleen Notario
 PLATFORM:

Windows 2000, XP, Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  TECHNICAL DETAILS

File Size: 73,728 bytes
File Type: DLL
Memory Resident: Yes
Initial Samples Received Date: 07 Oct 2010

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{random string} = rundll32.exe "{malware path and filename}"

HKEY_USERS\.DEFAULT\Software\
Microsoft\Windows\CurrentVersion\
Run
{random string} = rundll32.exe "{malware path and filename}"

HKEY_USERS\S-1-5-18\Software\
Microsoft\Windows\CurrentVersion\
Run
{random string} = rundll32.exe "{malware path and filename}

  SOLUTION

Minimum Scan Engine: 8.900
VSAPI OPR PATTERN File: 7.520.06
VSAPI OPR PATTERN Date: 07 Oct 2010

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 TROJ_VUNDO.ITB

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • {random string}=rundll32.exe {malware path and filename}
  • In HKEY_USERS\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Run
    • {random string}=rundll32.exe {malware path and filename}
  • In HKEY_USERS\S-1-5-18\Software\Microsoft\Windows\CurrentVersion\Run
    • {random string}=rundll32.exe {malware path and filename}

Step 5

Search and delete the file detected as TROJ_VUNDO.ITB

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files in the search result.


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