Analysis by: Anthony Joe Melgarejo
ALIASES:

Virus:DOS/Happy.412 (Microsoft), Happy.412 (McAfee), Happy (2) (Symantec)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

 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 by appending its code to target host files.

  TECHNICAL DETAILS

File Size: Varies
File Type: COM
Initial Samples Received Date: 19 Nov 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.

File Infection

This file infector infects the following file types:

  • COM

It infects by appending its code to target host files.

NOTES:

It displays the following strings in command line:

Thank you for running the Happy virus
Warning !!! COM-files in current directory
and C:\DOS might be infected !!!!

  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

Scan your computer with your Trend Micro product to clean files detected as HAPPY-3. 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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