Analysis by: Rika Joi Gregorio
 Modified by: Rhena Inocencio
ALIASES:

Win32/Caphaw.J trojan (ESET), Troj/CaphLNK-B (Sophos)

 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: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware

This Trojan may be dropped by other malware.

It is a component of other malware.

  TECHNICAL DETAILS

File Size: Varies
File Type: LNK
Initial Samples Received Date: 18 Jan 2013
Payload: Drops files

Arrival Details

This Trojan may be dropped by other malware.

Installation

This Trojan is a component of other malware.

NOTES:

This is the Trend Micro detection for specially crafted .LNK files that are used to execute dropped copies of the malware BKDR_CAPHAW once this shortcut is accessed.

The target property of the .LNK file contains this format:

  • %System%\cmd.exe /C start cmd.exe /C if exist {malware path and file name} start {malware path and file name} start{User's original folder or file}

It executes both the malware BKDR_CAPHAW and the original file or folder to trick users into thinking that the .LNK file is a legitimate file or folder.

As a result, the routines of the main component file is exhibited on the affected system.

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 9.664.04
FIRST VSAPI PATTERN DATE: 18 Jan 2013
VSAPI OPR PATTERN File: 9.665.00
VSAPI OPR PATTERN Date: 19 Jan 2013

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 that dropped/downloaded LNK_CAPCHAW.SM

     
    • BKDR_CAPHAW

Step 3

Scan your computer with your Trend Micro product to delete files detected as LNK_CAPCHAW.SM 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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