WORM_VOBFUS.AEO
Worm:Win32/Vobfus.PX (Microsoft), W32/Vobfus.GEW.worm (Panda), a variant of Win32/VBObfus.NI trojan (Esset)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
![](/vinfo/imgFiles/legend.jpg)
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 an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
TECHNICAL DETAILS
304,640 bytes
EXE
Yes
28 Apr 2013
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:
- %User Profile%\{Random}.exe
(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.)
It drops the following files:
- {drive letter}:\x.mpeg
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
{Random} = "%User Profile%\{Random}.exe /c"
Other System Modifications
This worm adds the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\WindowsUpdate
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\WindowsUpdate\
AU
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\WindowsUpdate\
AU
NoAutoUpdate = "1"
Propagation
This worm drops the following copy(ies) of itself in all removable drives:
- {drive letter}:\Passwords.exe
- {drive letter}:\Secret.exe
- {drive letter}:\Porn.exe
- {drive letter}:\Sexy.exe
- {drive letter}:\{Random}.exe
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
The said .INF file contains the following strings:
{garbage characters}
[autorun]
{garbage characters}
open={Random}.exe
{garbage characters}
ACTION={Random number}
UseautopLAY=1
{garbage characters}
SOLUTION
9.300
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
Step 3
Delete this registry key
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\Policies\Microsoft\Windows
- WindowsUpdate
- WindowsUpdate
Step 4
Delete this registry value
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
- {Random} = "%System Root%\Documents and Settings\Administrator\{Random}.exe /c"
- {Random} = "%System Root%\Documents and Settings\Administrator\{Random}.exe /c"
Step 5
Search and delete AUTORUN.INF files created by WORM_VOBFUS.AEO that contain these strings
[autorun]
{garbage characters}
open={Random}.exe
{garbage characters}
ACTION={Random number}
UseautopLAY=1
{garbage characters}
Step 6
Search and delete this file
- {drive letter}:\x.mpeg
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_VOBFUS.AEO. 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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