Analysis by: Rika Joi Gregorio

 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:
 INFORMATION EXPOSURE:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel: Via email

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

  TECHNICAL DETAILS

File Size: 2,507 bytes
File Type: LNK
Memory Resident: No
Initial Samples Received Date: 21 Aug 2013
Payload: Drops files

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

Installation

This Trojan drops and executes the following files:

  • %User Temp%\svchost.exe - detected as BKDR_SISPROC.A

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

NOTES:

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

%systemroot%\system32\cmd.exe /c copy /y /b "%cd%\Pre-Summit1\~$1.dat"+"%cd%\Pre-Summit1\~$2.dat" %temp%\svchost.exe"
start "%temp%\svchost.exe
explorer "%cd%\Pre-Summit1"

Upon execution, it opens a window which displays the files under Pre-Summit1 folder to hide its malicious routines from the user.

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 10.230.03
FIRST VSAPI PATTERN DATE: 21 Aug 2013
VSAPI OPR PATTERN File: 10.231.00
VSAPI OPR PATTERN Date: 22 Aug 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 malware/grayware files dropped/downloaded by LNK_SISPROC.A

     
    • BKDR_SISPROC.A

Step 3

Scan your computer with your Trend Micro product to delete files detected as LNK_SISPROC.A. 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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