TROJ_CLARETOR.AM

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 is injected into all running processes to remain memory resident.

It deletes the initially executed copy of itself.

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%\{random hexadecimal number}-{random digit}.tmp
• %User Profile%\{random hexadecimal number}-{random digit}.exe

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.. %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

It is injected into all running processes to remain memory resident.

It terminates the execution of the copy it initially executed and executes the copy it drops instead.

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
Windows Update Server = "%User Profile%\{random hexadecimal number}-{random digit}.exe"

Other Details

This Trojan deletes the initially executed copy of itself

NOTES:

It monitors the network activity of the processes it hooks. It looks for the strings google-analytics.com/ga.js and www.google-analytics.com/ga.js. If found, it replaces them with {BLOCKED}xscanner89.com/ga.js.