Analysis by: Sabrina Lei Sioting
 Modified by: Erika Bianca Mendoza
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: File infector

  • Destructiveness: No

  • Encrypted:

  • 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.

It infects files by overwriting code in the entry point and saving the overwritten code in the virus body. It then appends the virus body to the host file. It infects certain file types by inserting code in the said files.

  TECHNICAL DETAILS

File Size: Varies
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 22 Apr 2011
Payload: Modifies files

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.

File Infection

This file infector infects files by overwriting code in the entry point and saving the overwritten code in the virus body. It then appends the virus body to the host file.

It infects files with the following file extensions by inserting code in the said files:

  • .exe

NOTES:
This malware may arrive in the system when infected files are executed.

  SOLUTION

Minimum Scan Engine: 8.900
FIRST VSAPI PATTERN FILE: 8.112.04
FIRST VSAPI PATTERN DATE: 22 Apr 2011
VSAPI OPR PATTERN File: 8.113.00
VSAPI OPR PATTERN Date: 23 Apr 2011

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 PE_EXPIRO.SANA. 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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