WORM_OTORUN.XXQJ
Worm:Win32/Vobfus (Microsoft); W32/Refroso.AGEA!tr (Fortinet)
Windows

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.
TECHNICAL DETAILS
159,744 bytes
EXE
20 May 2015
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 filename}.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 creates the following folders:
- {drive letter}:\Games
- {drive letter}:\Sexy
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 file name}.exe = "%User Profile%\{random file name}.exe /{random character}"
It drops the following files:
- {random filename}.ico
- x.mpeg
Other System Modifications
This worm adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\WindowsUpdate\
AU
NoAutoUpdate = "1"
It modifies the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = "0"
Propagation
This worm 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:
The said .INF file contains the following strings:
{garbage characters}
[autorun]
action={random number}
{garbage characters}
open={random filename}.exe
{garbage characters}
useautoplay=1
{garbage characters}
NOTES:
It also uses the names of existing folders and names of files with the following extensions:
- mp3
- avi
- wma
- wmv
- wav
- mpg
- mp4
- doc
- txt
- xls
- jpg
- jpe
- bmp
- gif
- tif
- png
This malware drops .LNK files in removable drives that point to a copy of itself. This is done to trick users into clicking the shorcut files and execute the malware copy. These .LNK files use the following file names:
- Secret Folder.lnk
- Favourites.lnk
- Private.lnk
- Passwords.lnk
- Movies.lnk
- Music.lnk
- Search.lnk
- Pictures.lnk