WORM_VOBFUS.DK
Trojan.Win32.Diple.ejmc, Trojan.Win32.Diple.ejmc [Kaspersky]; Worm:Win32/Vobfus.gen!N [Microsoft]; W32.Changeup!gen15 [Symantec];
Windows 2000, Windows, XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Worm
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This worm arrives by connecting affected removable drives to a system. It 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 removable drives. These dropped copies use the names of the folders located on the said drives for their file names. 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
Arrival Details
This worm arrives by connecting affected removable drives to a system.
It 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 Profile%\{random name}.exe
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)
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 name} = "%User Profile%\{random name}.exe /x"
Other System Modifications
This worm adds the following registry entries as part of its installation routine:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\WindowsUpdate\
AU
NoAutoUpdate = "1"
It adds the following registry keys as part of its installation routine:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\WindowsUpdate
It modifies the following registry entries to hide files with Hidden attributes:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = "0"
(Note: The default value data of the said registry entry is 1.)
Propagation
This worm drops the following copy(ies) of itself in all removable drives:
- {random name}.exe
- Passwords.exe
- Porn.exe
- Secret.exe
- Sexy.exe
It drops copies of itself in removable drives. These dropped copies use the names of the folders located on the said drives for their file names.
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]
ICoN={random name}.exe,0
;garbage characters
open={random name}.eXE
;garbage characters
uSEaUTOPLaY=1
;garbage characters
NOTES:
It also drops the following files in all removable drives:
- X.MPEG
SOLUTION
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
Scan your computer with your Trend Micro product and note files detected as WORM_VOBFUS.DK
Step 3
Restart in Safe Mode
Step 4
Delete the registry entry with an unknown data 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 name} = "%User Profile%\{random name}.exe /x"
- {random name} = "%User Profile%\{random name}.exe /x"
Step 5
Restore this modified 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\Explorer\Advanced
- From: ShowSuperHidden = "0"
To: ShowSuperHidden = 1
- From: ShowSuperHidden = "0"
Step 6
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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.
- In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows
- WindowsUpdate
- WindowsUpdate
Step 7
Search and delete this file
- {drive letter}\x.mpeg
Step 8
Search and delete AUTORUN.INF files created by WORM_VOBFUS.DK that contain these strings
Step 9
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_VOBFUS.DK. 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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