ALIASES:

PWS:Win32/Lmir (Microsoft); [0001fb54.EXE]:PWS-LegMir.dll, [00010754.EXE]:PWS-LegMir.gen (McAfee); Infostealer.Lemir.H (Symantec); Trojan-GameThief.Win32.Lmir.aff (Kaspersky); Trojan.Win32.Generic.pak!cobra (Sunbelt); Trojan horse PSW.Legendmir.22.AD (AVG)

 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.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size: 76,800 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 08 May 2013

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:

  • %System%\SVCH0ST.EXE
  • %System%\Objectsl.WIX

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CLASSES_ROOT\CLSID\{081FE200-A103-11D7-A46D-C770E4459F2F}

HKEY_CLASSES_ROOT\CLSID\{081FE200-A103-11D7-A46D-C770E4459F2F}\
InprocServer32

HKEY_CLASSES_ROOT\Prgusel1.classname

HKEY_CLASSES_ROOT\Prgusel1.classname\Clsid

HKEY_CLASSES_ROOT\CLSID\{081FE200-A103-11D7-A46D-C770E4459F2F}\
ProgID

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
ShellExecuteHooks
{081FE200-A103-11D7-A46D-C770E4459F2F} = "hookmir"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{081FE200-A103-11D7-A46D-C770E4459F2F}\InprocServer32
ThreadingModel = "Apartment"

Dropping Routine

This Trojan drops the following files:

  • %System%\Prgusel0.wix
  • %System%\Prgusel1.wix
  • %System Root%\$$336699.bat

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

Other Details

This Trojan deletes itself after execution.

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.300

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

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\CLSID
    • {081FE200-A103-11D7-A46D-C770E4459F2F}
  • In HKEY_CLASSES_ROOT\CLSID\{081FE200-A103-11D7-A46D-C770E4459F2F}
    • InprocServer32
  • In HKEY_CLASSES_ROOT
    • Prgusel1.classname
  • In HKEY_CLASSES_ROOT\Prgusel1.classname
    • Clsid
  • In HKEY_CLASSES_ROOT\CLSID\{081FE200-A103-11D7-A46D-C770E4459F2F}
    • ProgID

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\Explorer\ShellExecuteHooks
    • {081FE200-A103-11D7-A46D-C770E4459F2F} = "hookmir"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{081FE200-A103-11D7-A46D-C770E4459F2F}\InprocServer32
    • ThreadingModel = "Apartment"

Step 4

Search and delete these components

[ Learn More ]
There may be some components 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%\Prgusel0.wix
  • %System%\Prgusel1.wix
  • %System Root%\336699.bat
336699.bat
  • In the Look In drop-down list, select My Computer then press Enter.
  • Once located, select the file then press SHIFT+DELETE to delete it.
  • Repeat the said steps for all files listed.

    • • For Windows Vista and Windows 7 users:

    1. Click Start>Computer.
    2. In the Search input box, type:
      • %System%\Prgusel0.wix
      • %System%\Prgusel1.wix
      • %System Root%\336699.bat
    3. Once located, select the file then press SHIFT+DELETE to delete it.
    4. Repeat the said steps for all files listed.
      *Note: Read the following Microsoft page if these steps do not work on Windows 7.

    Step 5

    Scan your computer with your Trend Micro product to delete files detected as TROJ_LEGMIR.CN. 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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