RANSOM_CERBER.SMSA

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.

It deletes itself after execution. It is capable of encrypting files in the affected system.

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:

• %Application Data%\{random characters}\{random filename}.exe

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on 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.)

It drops the following files:

• %User Temp%\3.bmp
• %Application Data%\{random characters}\Component_00
• %Application Data%\{random characters}\Component_01
• {Folder of encrypted files}\# DECRYPT MY FILES #.html
• {Folder of encrypted files}\# DECRYPT MY FILES #.txt
• {Folder of encrypted files}\# DECRYPT MY FILES #.url
• {Folder of encrypted files}\# DECRYPT MY FILES #.vbs
• %Desktop%\# DECRYPT MY FILES #.html
• %Desktop%\# DECRYPT MY FILES #.txt
• %Desktop%\# DECRYPT MY FILES #.url
• %Desktop%\# DECRYPT MY FILES #.vbs

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on 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.. %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on 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.. %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.)

It creates the following folders:

• %Application Data%\{random characters}

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on 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_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random filename} = "%Application Data%\{random characters}\{random filename}.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
{random filename} = “%Application Data%\{random characters}\{random filename}.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
Run = "%Application Data%\{random characters}\{random filename}.exe"

It drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:

• %User Startup%\{random filename}.lnk

(Note: %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.)

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Command Processor
AutoRun = "%Application Data%\{random characters}\{random filename}.exe"

HKEY_CURRENT_USER\Control Panel\Desktop
SCRNSAVE.EXE = "%Application Data%\{random characters}\{random filename}.exe"

Other Details

This Trojan connects to the following URL(s) to get the affected system's IP address:

• http://ip-api.com/json

It renames encrypted files using the following names:

• {random characters}.cerber2

It deletes itself after execution.

It is capable of encrypting files in the affected system.

NOTES:

{random filename} is a name of an executable file in the %System% folder.