Analysis by: kathleenno

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

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 the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

  TECHNICAL DETAILS

File Size: 112,184 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 28 Jul 2011
Payload: Downloads files

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:

  • %User Profile%\Application Data\Microsoft\Crypto\DES64v5\msieckc.exe - also detected as TROJ_MOTMOT.M
  • %User Profile%\Application Data\Microsoft\IME\V2005\PHIME2002A.exe - also detected as TROJ_MOTMOT.M
  • %User Temp%\automngr.exe - also detected as TROJ_MOTMOT.M
  • %User Temp%\rstimgr.dll - also detected as TROJ_MOTMOT.M
  • %User Temp%\rstimgr.inf - non-malicious file
  • %User Temp%\smcnmgr.exe - detected as WORM_OTORUN.KEN
  • %User Temp%\winmsgr.exe - also detected as TROJ_MOTMOT.M

(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.. %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 creates the following folders:

  • %User Profile%\Application Data\Microsoft\IME\V2005
  • %User Profile%\Application Data\Microsoft\Crypto\DES64v5

(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:

  • 20110617
  • 720110613
  • 820110615

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
{malware filename} = "{malware path and filename}"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
PHIME2002A.exe = "%User Profile%\Application Data\Microsoft\IME\V2005\PHIME2002A.exe"

Dropping Routine

This Trojan executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

Download Routine

This Trojan connects to the following website(s) to download and execute a malicious file:

  • http://wwvv.{BLOCKED}led.net/minor/txt/read.php
  • http://wwvv.{BLOCKED}led.net/minor/images/view.php

It saves the files it downloads using the following names:

  • %Current%\ctfmon.exe - also detected as TROJ_MOTMOT.M

NOTES:

It connects to the following site to report system infection:

  • http://{BLOCKED}il.ns01.biz/bin/read_a.php

It checks if the following files are present in the affected system:

  • %User Temp%\CR_1.tmp\dtlcntr.exe
  • %User Temp%\CR_1.tmp\googletoolbar.exe
  • %User Temp%\CR_1.tmp\active.dll
  • %User Temp%\CR_1.tmp\detect.dll

  SOLUTION

Minimum Scan Engine: 8.900
FIRST VSAPI PATTERN FILE: 8.317.00
FIRST VSAPI PATTERN DATE: 28 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

Remove malware files dropped/downloaded by TROJ_MOTMOT.M

    WORM_OTORUN.KEN

Step 3

Identify and terminate files detected as TROJ_MOTMOT.M

[ 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 4

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\RunOnce
    • {malware filename} = "{malware path and filename}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • PHIME2002A.exe = "%User Profile%\Application Data\Microsoft\IME\V2005\PHIME2002A.exe"

Step 5

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %User Profile%\Application Data\Microsoft\Crypto\DES64v5
  • %User Profile%\Application Data\Microsoft\IME\V2005

Step 6

Search and delete this file

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files and folders in the search result.
  • %User Temp%\rstimgr.inf

Step 7

Scan your computer with your Trend Micro product to delete files detected as TROJ_MOTMOT.M. 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:

RECOMMENDATION


General Recommendation

  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:

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

  3. 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:
  4. Enable firewall to protect against threats. For more information, refer to How do I enable or disable the Personal Firewall of Trend Micro
  5. Block unused ports to disallow malware from using these ports to communicate and/or enforce commands.
  6. Avoid accessing the listed malicious URLs to prevent possible re-infection.
  7. Monitor network connections for any suspicious connection or connectivity.
  8. Regularly update list of sites that are trusted.
  9. Clear browser cache and delete cookies regularly.
  10. Delete files in the %User Temp% folder.


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