ALIASES:

Worm:Win32/Autorun.gen!VW (Microsoft); Generic Malware.cm (McAfee); Infostealer (Symantec); Trojan-GameThief.Win32.Lmir.awg (Kaspersky); BehavesLike.Win32.Malware.sst (mx-v) (Sunbelt); Found Luhe.Packed.A (AVG)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This spyware 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: 14,477 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 09 May 2013

Arrival Details

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

  • %System%\winasse.exe

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

It creates the following folders:

  • %System%\GroupPolicy
  • %System%\GroupPolicy\Machine
  • %System%\GroupPolicy\Machine\Scripts

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

Other System Modifications

This spyware adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run

HKEY_LOCAL_MACHINE\SOFTWARE\wSkysoft

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run
KernelCheck = "%System%\winasse.exe"

Other Details

This spyware 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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer
    • Run
  • In HKEY_LOCAL_MACHINE\SOFTWARE
    • wSkysoft

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\policies\Explorer\Run
    • KernelCheck = "%System%\winasse.exe"

Step 4

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.
  • %System%\GroupPolicy
  • %System%\GroupPolicy\Machine
  • %System%\GroupPolicy\Machine\Scripts

Step 5

Scan your computer with your Trend Micro product to delete files detected as TSPY_LEGMIR.WK. 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.


Did this description help? Tell us how we did.