WORM_VOBFUS.ELI
Worm.Win32.Vobfus.bncj (Kaspersky)
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 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 an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
TECHNICAL DETAILS
245,760 bytes
EXE
Yes
20 Dec 2012
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%\runme.exe
- %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 file(s)/component(s):
- {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 /{random letter}"
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 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:
- {drive letter}:\{random file name}.exe
- {drive letter}:\Passwords.exe
- {drive letter}:\Porn.exe
- {drive letter}:\Secret.exe
- {drive letter}:\Sexy.exe
- {drive letter}:\{folder name}.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]
icon={random}.exe,0
{garbage characters}
open={random}.eXE
{garbage characters}
ACTION=18480
{garbage characters}
UseautopLAY=1
{garbage characters}
Other Details
This worm connects to the following possibly malicious URL:
- http://58341.{BLOCKED}z.net:8080/{random characters}?{random character}
- http://DOMAIN.{BLOCKED}z.net:8080/{random characters}/?{random character}
- http://ns1.{BLOCKED}te3.com
- http://time.{BLOCKED}z.net
NOTES:
This worm searches for folders in all removable drives then drops copies of itself as {folder name}.exe.
It also uses the file names of files with the following extensions:
- .avi
- .bmp
- .doc
- .gif
- .jpe
- .jpg
- .mp3
- .mp4
- .mpg
- .png
- .tif
- .txt
- .wav
- .wma
- .wmv
- .xls
It then sets the attribute of the original file or folder to Hidden and System to trick users into thinking that the dropped copy is the legitimate file or folder.
SOLUTION
9.300
9.740.05
20 Feb 2013
9.741.00
21 Feb 2013
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_VOBFUS.ELI
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 file name} = "%User Profile%\{random file name}.exe /{random character}"
- {random file name} = "%User Profile%\{random file name}.exe /{random character}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU
- NoAutoUpdate = "1"
- NoAutoUpdate = "1"
Step 5
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out 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
Search and delete AUTORUN.INF files created by WORM_VOBFUS.ELI that contain these strings
Step 7
Search and delete this file
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.
- {drive letter}:\x.mpeg
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_VOBFUS.ELI. 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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