TROJ_ADCLICK.MF


 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This Trojan may be unknowingly downloaded by a user while visiting malicious websites.

  TECHNICAL DETAILS

File Size:

60,928 bytes

File Type:

EXE

File Compression:

Delphi

Memory Resident:

Yes

Initial Samples Received Date:

04 Jan 2012

Payload:

Drops files

Arrival Details

This Trojan may be unknowingly downloaded by a user while visiting malicious websites.

Installation

This Trojan drops the following copies of itself into the affected system:

  • %SystemRoot%\Documents and Settings\All Users\defragdefrag.exe
  • %Application Data%\Managechar.exe
  • %User Temp%\AdapterSched.exe

(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.. %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.)

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

  • og5trjg85gu54t7

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
jusched = {malware path and filename}

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
\defragdefrag.exe = %SystemRoot%\Documents and Settings\All Users\defragdefrag.exe

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
\Managechar.exe = %Application Data%\Managechar.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
jusched = {malware path and filename}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
\defragdefrag.exe = %SystemRoot%\Documents and Settings\All Users\defragdefrag.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
\Managechar.exe = %Application Data%\Managechar.exe

NOTES:
It connects to the following URL via HTTP GET to access other advertisement sites and possibly download other files into the system. However, during testing, no files were downloaded.

  • http://{BLOCKED}con.net/adv.php?i=12&rnd={random number}

The random number is based on the system time.

  SOLUTION

Minimum Scan Engine:

9.200

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

Identify and terminate files detected as TROJ_ADCLICK.MF

[ Learn More ]
  1. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  2. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • jusched = {malware path and filename}
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • \defragdefrag.exe = %SystemRoot%\Documents and Settings\All Users\defragdefrag.exe
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • \Managechar.exe = %Application Data%\Managechar.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • jusched = {malware path and filename}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • \defragdefrag.exe = %SystemRoot%\Documents and Settings\All Users\defragdefrag.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • \Managechar.exe = %Application Data%\Managechar.exe

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_ADCLICK.MF. 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.

NOTES:

Recommendations

1. This malware is detected and removed by the latest Trend Micro anti-malware engine and pattern. Always keep pattern files and engines up-to-date. To know more about updating your Trend Micro product’s pattern, please refer to the following Trend Micro support page:

  • http://esupport.trendmicro.com/9/How-do-I-manually-update-the-virus-pattern-of-my-Trend-Micro-Internet.aspx

Note: The steps apply for specific products indicated in the page.

2. To actively detect and protect your machine, enable real-time scanning of your Trend Micro anti-malware product. Refer to the following Trend Micro support page to know more about enabling real-time scanning in your Trend Micro product:

  • Home Users: http://esupport.trendmicro.com/solution/en-us/1054798.aspx
  • Business Users: http://esupport.trendmicro.com/Pages/How-do-I-enable-or-disable-the-Real-time-Protection-of-Trend-M-EN-1038331.aspx

3. Enable firewall to protect against threats:

  • http://esupport.trendmicro.com/3/How-do-I-enable-or-disable-the-Personal-Firewall-of-Trend-Micr-EN-1038273.aspx

4. Keep software and operating systems updated with latest patches released by vendors to address vulnerabilities and exploits.

5. Block unused ports to disallow malware from using these ports to communicate and/or enforce commands.

6. Be aware of social engineering attacks.

7. Avoid accessing the listed malicious URLs to prevent possible re-infection.

8. Monitor network connections for any suspicious connection or connectivity.

9. Regularly update list of sites that are trusted.

10. Avoid downloading software cracks and/or pirated applications.


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