WORM_VOBFUS.TT
Worm:Win32/Vobfus (Microsoft), Worm.Win32.Vobfus.amyv (Kaspersky), Win32/Pronny.JB worm (Eset)
Windows 2000, Windows XP, Windows Server 2003
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
364,544 bytes
EXE
Yes
12 Dec 2012
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.)