TROJ_HILOTI

This description is based is a compiled analysis of several variants of TROJ_HILOTI. Note that specific data such as file names and registry values may vary for each variant.

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.

As of this writing, the said sites are inaccessible.

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:

• %Windows%\{random name}.dll
• %User Profile%\Local Settings\Application Data\{Random CLSID for Firefox}\chrome.manifest - non-malicious file
• %User Profile%\Local Settings\Application Data\{Random CLSID for Firefox}\chrome\content\_cfg.js - non-malicious file
• %User Profile%\Local Settings\Application Data\{Random CLSID for Firefox}\chrome\content\overlay.xul - detected as JS_GORD.F
• %User Profile%\Local Settings\Application Data\{Random CLSID for Firefox}\install.rdf - non-malicious file

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.. %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 creates the following folders:

• %Application Data%\{Random CLSID for Firefox}

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

It injects itself into the following processes as part of its memory residency routine:

• explorer.exe

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} = "rundll32.exe "{malware path and file name}",Startup"

Other System Modifications

This Trojan adds the following registry keys as part of its installation routine:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\{random characters}

Download Routine

This Trojan accesses the following websites to download files:

• {BLOCKED}db103a.{BLOCKED}ro.net
• {BLOCKED}7db1000.{BLOCKED}ero.net
• {BLOCKED}db1000.{BLOCKED}zy.net
• {date-time}.{BLOCKED}zy.net/get2.php
• http://{BLOCKED}db0904.meetri.net/get2.php
• http://{BLOCKED}b0905.gabcat.net/get2.php

As of this writing, the said sites are inaccessible.

NOTES:

This description is based is a compiled analysis of several variants of TROJ_HILOTI. Note that specific data such as file names and registry values may vary for each variant.