TSPY_MEXN.A

September 07, 2013
 ALIASES:

Trojan:Win32/Sisron (Microsoft); RDN/Ransom!ck (McAfee); Trojan Horse (Symantec); Trojan-Ransom.Win32.Foreign.byat (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse PSW.Generic11.JLR (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.

  TECHNICAL DETAILS

File Size:

892,928 bytes

File Type:

EXE

Memory Resident:

Yes

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 creates the following folders:

  • %User Profile%\Common Files

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Autostart Technique

This spyware adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
openv = "%User Profile%\Common Files\openv.exe"

Other System Modifications

This spyware deletes the following files:

  • %Temp%\scs3.tmp
  • %Temp%\scs6.tmp

(Note: %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp.)

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

Restart in Safe Mode

[ Learn More ]

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\Run
    • openv = "%User Profile%\Common Files\openv.exe"

Step 4

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.
  • %User Profile%\Common Files

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_MEXN.A. 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 6

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.

  • %Temp%\scs3.tmp
  • %Temp%\scs6.tmp


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