Analysis by: Karl Dominguez


Windows 2000, XP, Server 2003


  • Threat Type: File infector

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes


This file infector infects by inserting its code to unused space in host files.


File Size: Varies
File Type: PE
Memory Resident: Yes
Initial Samples Received Date: 06 Sep 2010
Payload: Modifies files

Autostart Technique

This file infector drops the following file(s) in the Windows Startup folder to enable its automatic execution at every system startup:

  • {random name}.exe

Other System Modifications

This file infector adds the following registry entries as part of its installation routine:

Microsoft = 1

File Infection

This file infector infects by inserting its code to unused space in host files.

Other Details

This file infector does the following:

  • Infects running processes. Infected files are detected as PE_LICAT.SM


Minimum Scan Engine: 8.900
VSAPI OPR PATTERN File: 7.519.00
VSAPI OPR PATTERN Date: 07 Oct 2010

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

Remove the malware/grayware file dropped/downloaded by PE_LICAT.SM-O


Step 3

Identify and terminate files detected as PE_LICAT.SM-O

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. 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.
  3. 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
    • Microsoft=1

Step 5

Scan your computer with your Trend Micro product to delete files detected as PE_LICAT.SM-O. 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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