TROJ_SUSPECT.PMF


 ALIASES:

PAK:UPX (Kaspersky); BehavesLike.Win32.Malware.tsc (mx-v) (Sunbelt); Gen:Trojan.Heur.D.dmHfbOkkaWb (FSecure)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • 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.

  TECHNICAL DETAILS

File Size:

61,825 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

17 Apr 2012

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:

  • D:\Downloads\system.exe
  • %Program Files%\Common Files\Microsoft Shared\MSInfo\system.exe

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)

It creates the following folders:

  • D:\Downloads

Other System Modifications

This Trojan deletes the following files:

  • %User Profile%\×ÀÃæ\360ɱ¶¾.lnk
  • %User Profile%\×ÀÃæ\360°²È«ÎÀÊ¿.lnk

(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 registry keys:

HKEY_CLASSES_ROOT\ini

HKEY_CLASSES_ROOT\ini\Shell\
Open\Command

HKEY_CLASSES_ROOT\ini\DefaultIcon

HKEY_CLASSES_ROOT\urlchm

HKEY_CLASSES_ROOT\urlchm\Shell\
Open\Command

HKEY_CLASSES_ROOT\urlchm\DefaultIcon

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
ini
EditFlags = "2"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
urlchm
EditFlags = "2"

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Shell Folders
Startup = "D:\Downloads"

(Note: The default value data of the said registry entry is %User Profile%\Start Menu\Programs\Startup.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
User Shell Folders
Startup = "D:\Downloads"

(Note: The default value data of the said registry entry is {random values}.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
User Shell Folders
Templates = "%USERPROFILE%\Templates"

(Note: The default value data of the said registry entry is {random values}.)

Dropping Routine

This Trojan drops the following files:

  • %System Root%\1.reg
  • %System Root%\2.reg

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

This report is generated via an automated analysis system.

  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

Delete this registry key

[ 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_CLASSES_ROOT
    • ini
  • In HKEY_CLASSES_ROOT\ini\Shell\Open
    • Command
  • In HKEY_CLASSES_ROOT\ini
    • DefaultIcon
  • In HKEY_CLASSES_ROOT
    • urlchm
  • In HKEY_CLASSES_ROOT\urlchm\Shell\Open
    • Command
  • In HKEY_CLASSES_ROOT\urlchm
    • DefaultIcon

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\Classes\ini
    • EditFlags = "2"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\urlchm
    • EditFlags = "2"

Step 4

Restore this modified 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\Explorer\Shell Folders
    • From: Startup = "D:\Downloads"
      To: Startup = ""%User Profile%\Start Menu\Programs\Startup""
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders
    • From: Startup = "D:\Downloads"
      To: Startup = ""{random values}""
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders
    • From: Templates = "%USERPROFILE%\Templates"
      To: Templates = ""{random values}""

Step 5

Search and delete these files

[ 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.
  • %System Root%\1.reg
  • %System Root%\2.reg

Step 6

Search and delete this folder

[ 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.
  • D:\Downloads

Step 7

Scan your computer with your Trend Micro product to delete files detected as TROJ_SUSPECT.PMF. 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.

Step 8

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %User Profile%\×ÀÃæ\360ɱ¶¾.lnk
  • %User Profile%\×ÀÃæ\360°²È«ÎÀÊ¿.lnk


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