TROJ_CUTWAIL.XZO

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 executes then deletes itself afterward.

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:

• %All Users Profile%\{random folder name 3}\{random filename 3}.{random extension name 1}
• %All Users Profile%\{random folder name 4}\{random filename 4}.{random extension name 2}
• %All Users Profile%\{random folder name 5}\{random filename 5}.{random extension name 3}
• %ProgramData%\{random folder name 3}\{random filename 3}.{random extension name 1} (Windows Vista and higher versions)
• %ProgramData%\{random folder name 4}\{random filename 4}.{random extension name 2} (Windows Vista and higher versions)
• %ProgramData%\{random folder name 5}\{random filename 5}.{random extension name 3} (Windows Vista and higher versions)
• %Windows%\xzlj.xzt

(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.. %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This is usually C:\ProgramData in Windows Vista and 7, or C:\Program Files on Windows 2000, XP (32-bit), and Server 2003, or C:\Program Files (x86) on Windows XP (64-bit).. %Windows% is the Windows folder, which is usually C:\Windows.)

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

• %All Users Profile%\{random folder name 1}\{random filename 1}.exe
• %All Users Profile%\{random folder name 2}\{random filename 2}.exe
• %ProgramData%\{random folder name 1}\{random filename 1}.exe (Windows Vista and higher versions)
• %ProgramData%\{random folder name 2}\{random filename 2}.exe (Windows Vista and higher versions)

(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.. %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This is usually C:\ProgramData in Windows Vista and 7, or C:\Program Files on Windows 2000, XP (32-bit), and Server 2003, or C:\Program Files (x86) on Windows XP (64-bit).)

It creates the following folders:

• %All Users Profile%\{random folder name 1}
• %All Users Profile%\{random folder name 2}
• %All Users Profile%\{random folder name 3}
• %All Users Profile%\{random folder name 4}
• %All Users Profile%\{random folder name 5}
• %ProgramData%\{random folder name 1} (Windows Vista and higher versions)
• %ProgramData%\{random folder name 2} (Windows Vista and higher versions)
• %ProgramData%\{random folder name 3} (Windows Vista and higher versions)
• %ProgramData%\{random folder name 4} (Windows Vista and higher versions)
• %ProgramData%\{random folder name 5} (Windows Vista and higher versions)

(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.. %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This is usually C:\ProgramData in Windows Vista and 7, or C:\Program Files on Windows 2000, XP (32-bit), and Server 2003, or C:\Program Files (x86) on Windows XP (64-bit).)

It executes then deletes itself afterward.

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\RunOnce
{random} = "%All Users Profile%\{random folder name 1}\{random filename 1}.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Winlogon
shell = "%All Users Profile%\{random folder name 2}\{random filename 2}.exe,explorer.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
{random} = "%ProgramData%\{random folder name 1}\{random filename 1}.exe" (Windows Vista and higher versions)

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Winlogon
shell = "%ProgramData%\{random folder name 2}\{random filename 2}.exe,explorer.exe" (Windows Vista and higher versions)

Other Details

This Trojan connects to the following possibly malicious URL:

• http://{BLOCKED}xwithjimmy.org
• http://{BLOCKED}ephjs.net
• http://{BLOCKED}ezfk.org