RANSOM_CRYPAURA.J
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
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.
TECHNICAL DETAILS
170,496 bytes
EXE
17 Mar 2016
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