WORM_VOBFUS.ALJ
Worm:Win32/Vobfus.RM (Microsoft), Worm.Win32.Luder.bvmn (Kaspersky), Win32/Pronny.LZ (ESET)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This worm arrives via removable drives. 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 modifies registry entries to hide files with System and Read-only attributes.
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 via removable drives.
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 file name}.exe
- %User Profile%\Passwords.exe
- %User Profile%\Porn.exe
- %User Profile%\Sexy.exe
- %User Profile%\Secrets.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 name} = "%User Profile%\{random file name}.exe"
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 System and Read-only 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 file name}.exe
- Passwords.exe
- Porn.exe
- Sexy.exe
- Secrets.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:
[autorun]
open={random file name}.exe
action{random number}
useautoplay=1
Download Routine
This worm accesses the following websites to download files:
- http://{BLOCKED}f.com/p/KeyDll.exe