TROJ_CRILOCK.CI

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Arrival Details

This Trojan 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 Trojan drops the following files:

• {Folder Path}\README TO UNLOCK.txt

It drops the following copies of itself into the affected system:

• %User Temp%\Q92sPD97W8G9xnT.exe
• "%User Temp%\tEST.exe

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Alcmeter = "%User Temp%\Q92sPD97W8G9xnT.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CLASSES_ROOT\.LOCKED

HKEY_CLASSES_ROOT\OZOBUKHRXMOVNAR

HKEY_CLASSES_ROOT\OZOBUKHRXMOVNAR\DefaultIcon

HKEY_CLASSES_ROOT\OZOBUKHRXMOVNAR\shell\
open\command

HKEY_CURRENT_USER\Software\Adobe\
Adobe Acrobat\10.0

HKEY_CURRENT_USER\Software\Adobe\
Adobe Synchronizer\10.0

HKEY_LOCAL_MACHINE\System\Acrobatbrokerserverdispatchercpp789

HKEY_CURRENT_USER\Software\Adobe\
Acrobat Reader\10.0\Installer\
Migrated

NOTES:

This malware encrypts files and renames them to {filename and extension}.LOCKED.