Analysis by: Sabrina Lei Sioting
 Modified by: Michael Cabel
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: File infector

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This file infector 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: Varies
File Type: XLS
Initial Samples Received Date: 03 May 2012

Arrival Details

This file infector arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

NOTES:

The malicious macro script drops the file, STARTUP.XLS, a copy of the infected file in the Startup folder of the Microsoft Excel application.

It utilizes the auto_open macro command consequently infecting other workbooks once opened.

This script also intercepts the use of two function buttons in Microsoft Excel, namely the F8 and F11 buttons. Pressing these buttons allows the macro script to be executed.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.966.01
FIRST VSAPI PATTERN DATE: 03 May 2012
VSAPI OPR PATTERN File: 8.967.00
VSAPI OPR PATTERN Date: 03 May 2012

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

Scan your computer with your Trend Micro product to clean files detected as X97M_LAROUX.CO. 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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