RANSOM_CRYPAURA.J

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 copies of itself into the affected system and executes them:

• %System%\{malware filename}.exe
• %User Startup%\{malware filename}.exe

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)

It drops the following files:

• %User Profile%\How to decrypt your files.jpg
• %Desktop%\How to decrypt your files.txt

(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.. %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop in Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

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
{random characters} = %System%\{malware filename}.exe

Other System Modifications

This Trojan changes the desktop wallpaper by modifying the following registry entries:

HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = %User Profile%\How to decrypt your files.jpg

(Note: The default value data of the said registry entry is {User Preference}.)

HKEY_CURRENT_USER\Control Panel\Desktop
TileWallpaper = 0

(Note: The default value data of the said registry entry is {User Preference}.)

Other Details

This Trojan connects to the following possibly malicious URL:

• http://{BLOCKED}hs.cc/system/mix/007BGT/pass/index.php

It renames encrypted files using the following names:

• {original filename and extension}.ID{victim id}.[Ecovector3@aol.com].xtbl

NOTES:

This malware executes the following command to delete shadow copies:

vssadmin.exe Delete Shadows /All /Quiet