Analysis by: kathleenno
 Modified by: Christopher Daniel So
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This spyware adds certain strings to the Windows HOSTS file.

It hooks Windows API functions to make itself invisible in file searches.

This spyware also has rootkit capabilities, which enables it to hide its processes and files from the user.

  TECHNICAL DETAILS

File Size: Varies
File Type: PE
Memory Resident: Yes
Initial Samples Received Date: 06 Jul 2011
Payload: Modifies HOSTS file, Hides files and processes

Arrival Details

This spyware may be unknowingly downloaded by a user while visiting the following malicious websites:

  • http://{BLOCKED}g.info/chrome/download_chrome_11.0.696.68.php

Installation

This spyware drops the following files:

  • %User Profile%\Application Data\cleanhtm.exe
  • %User Profile%\Application Data\cleanhtm.dll

(Note: %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 adds the following mutexes to ensure that only one of its copies runs at any one time:

  • g4058h4pedojge

Autostart Technique

This spyware adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
cleanhtm = "%User Profile%\Application Data\cleanhtm.exe"

Rootkit Capabilities

This spyware also has rootkit capabilities, which enables it to hide its processes and files from the user.

HOSTS File Modification

This spyware adds the following strings to the Windows HOSTS file:

  • {BLOCKED}.{BLOCKED}.118.187 www.google.com
  • {BLOCKED}.{BLOCKED}.118.188 search.yahoo.com
  • {BLOCKED}.{BLOCKED}.118.188 www.bing.com

NOTES:

It accesses the following URL to notify the malicious user of its installation:

  • http://{BLOCKED}.{BLOCKED}.64.186/?id=29&v=5&c={computer name}&rs=1&h=1

It hooks the following Windows API functions to make itself invisible in file searches:

  • FindFirstFileA
  • FindNextFileA
  • FindFirstFileW
  • FindNextFileW

It hooks the following Native API functions to make its autostart registry invisible:

  • NtEnumerateValueKey

It hooks the following Native API functions to hide its own process:

  • NtResumeThread
  • NtQuerySystemInformation

It hooks the following Native API function to ensure that all hooks are installed in all loaded DLLs:

  • LdrLoadDll

It hooks the WinSock API function connect to redirect the connections from the following domain names to the IP address {BLOCKED}.{BLOCKED}.118.187:

  • www.google.com
  • search.yahoo.com
  • www.bing.com

  SOLUTION

Minimum Scan Engine: 8.900
FIRST VSAPI PATTERN FILE: 8.270.01
FIRST VSAPI PATTERN DATE: 06 Jul 2011

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Since this malware uses rootkit technology, detection and removal using normal and safe mode methods may not eliminate it completely. This procedure restarts the system using the Windows Recovery Console.

  1. Insert the Windows Installation CD into the CD drive, then Press the restart button.
  2. Upon prompt, press any key to boot from the CD.
  3. On the main menu, type r to go to the Recovery Console.
  4. Type the drive that contains Windows (usually C:) and press Enter.
  5. In the input box, type the following then press Enter:
    del %User Profile%\Application Data\cleanhtm.exe
  6. Type exit and press Enter to restart the system normally.

Step 3

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • cleanhtm = "%User Profile%\Application Data\cleanhtm.exe"

Step 4

Remove these strings added by the malware/grayware/spyware in the HOSTS file

[ Learn More ]
    {BLOCKED}.{BLOCKED}.118.187 www.google.com
    {BLOCKED}.{BLOCKED}.118.188 search.yahoo.com
    {BLOCKED}.{BLOCKED}.118.188 www.bing.com
"

Step 5

Scan your computer with your Trend Micro product to delete files detected as TSPY_ONLINEG.MU. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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