WORM_VOBFUS.TT
Worm:Win32/Vobfus (Microsoft), Worm.Win32.Vobfus.amyv (Kaspersky), Win32/Pronny.JB worm (Eset)
Windows 2000, Windows XP, Windows Server 2003
![](/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.
It modifies certain registry entries to hide Hidden files.
TECHNICAL DETAILS
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:
- %User Profile%\{random}.exe
- %User Profile%\Passwords.exe
- %User Profile%\Porn.exe
- %User Profile%\Secret.exe
- %User Profile%\Sexy.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:
- %User Profile%\msn.com
- {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:
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}\Porn.exe
- {drive letter}\Secret.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 numbers}
{garbage characters}
useaUTOPLAY=1
{garbage characters}
Other Details
This worm connects to the following possibly malicious URL:
- http://{BLOCKED}7.{BLOCKED}p.at:443/ObFoyyb?f
- {BLOCKED}1.{BLOCKED}ecks.com
It modifies the following registry entries to hide Hidden files:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = "0"
(Note: The default value data of the said registry entry is 1.)