TROJ_KRYPIL.BZC

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.

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:

• %User Temp%\system32\winreg.exe

(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.)

It creates the following folders:

• %User Temp%\system32
• %User Profile%\Application Data\Monitor
• %Program Files%\Client
• %User Profile%\Monitor\Logs
• %User Profile%\Monitor\Files
• %User Profile%\Monitor\Guard

(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.. %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.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

Other System Modifications

This Trojan deletes the following files:

• %User Temp%\svhost.exe
• %User Temp%\ svhost.exe
• %User Temp%\system32\winreg.exe:Zone.Identifier
• %User Startup%\winreg.exe:Zone.Identifier
• %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.892.1403109
• %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.892.1403109
• %User Profile%\v2.0.50727.42\security.config.cch.892.1403312
• %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.176.1436812
• %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.176.1436812
• %User Profile%\v2.0.50727.42\security.config.cch.176.1437593
• %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.1160.1485671
• %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.1160.1485671
• %User Profile%\v2.0.50727.42\security.config.cch.1160.1486218

(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.. %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.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %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 adds the following registry entries:

HKEY_CURRENT_USER\Software
23T08aNaJvPTde25sBg1ZQ== = "7VP1AaVnx5OR3RHc38xFTP58ArkEr/JwbzaFngrfsNc="

HKEY_CURRENT_USER\Software
KDim1V9SMvjb7HxuU1Sejw== = "S2TEt2G+9MqPEVdAV+MV+A=="

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
Load = "%User Temp%\system32\winreg.exe.lnk "

Dropping Routine

This Trojan drops the following files:

• %User Temp%\system32\winreg.exe.lnk
• %User Profile%\Guard\1
• %User Temp%\svhost.exe

(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.. %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.)

Other Details

This Trojan connects to the following possibly malicious URL:

• 204.152.219.89

It deletes itself after execution.

This report is generated via an automated analysis system.