Analysis by: Cris Nowell Pantanilla

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan is the malware component of a spam campaign that leverages the death of North Korean leader Kim Jong-Il.

To get a one-glance comprehensive view of the behavior of this Trojan, refer to the Threat Diagram shown below.

It arrives as an attachment to spammed mails.

Upon execution, it checks the version of the Adobe Acrobat on the system. If the version is 9.4 or below, it attempts to exploit the following vulnerabilities to drop and execute files:

It drops and opens a non-malicious PDF file to trick the user that the file is non-malicious.

This Trojan executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

  TECHNICAL DETAILS

File Size: 421,149 bytes
File Type: PDF
Initial Samples Received Date: 20 Dec 2011
Payload: Drops files

Installation

This Trojan drops the following component file(s):

  • %User Profile%\Local Settings\fabc.scr
  • %User Profile%\Local Settings\log1.txt
  • %User Profile%\Local Settings\abc.scr - BKDR_FYNLOS.A

(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

It drops the following non-malicious file:

  • %User Profile%\Local Settings\BriefintroductionofKim-Jong-il.pdf

(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

Dropping Routine

This Trojan executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

NOTES:

It arrives as an attachment to spammed mails:

It drops and opens a non-malicious PDF file to trick the user that the file is non-malicious:

Upon execution, it checks the version of the Adobe Acrobat on the system. If the version is 9.4 or below, it attempts to exploit the following vulnerabilities to drop and execute files:

It joins the files LOG1.TXT and FABC.SCR to form the file ABC.SCR which it executes afterwards.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.656.04
FIRST VSAPI PATTERN DATE: 20 Dec 2011
VSAPI OPR PATTERN File: 8.657.00
VSAPI OPR PATTERN Date: 21 Dec 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

Remove malware files dropped/downloaded by TROJ_PIDIEF.EGQ

Step 3

Scan your computer with your Trend Micro product to delete files detected as TROJ_PIDIEF.EGQ. 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.

Step 4

Download and apply these security patches Refrain from using these products until the appropriate patches have been installed. Trend Micro advises users to download critical patches upon release by vendors.


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