X2KM_DLOADER.JK

May 31, 2017
 Analysis by: Cris Nowell Pantanilla
 ALIASES:

VBA:Downloader-MA [Trj] (Avast), W97M.ShellCode.A (BitDefender), W97M.ShellCode.A (GData)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Spammed via email

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

As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

507,143 bytes

File Type:

DOC

Memory Resident:

Yes

Initial Samples Received Date:

30 May 2017

Payload:

Drops files, Connects to URLs/IPs

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 Profile%\Downloads\awareness.doc ← downloader
  • %User Profile%\Downloads\update.vbs ← executes awareness.doc
  • %User Startup%\start.vbs ← executes VBS file

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)

It adds the following processes:

  • rundll.exe

It injects codes into the following process(es):

  • rundll.exe

Download Routine

This Trojan connects to the following URL(s) to download its component file(s):

  • http://ec2-52-212-203-69.{BLOCKED}est-1.compute.{BLOCKED}aws.com/OUuC

As of this writing, the said sites are inaccessible.

NOTES:

This malware connects to the said remote site to download a shell code which it executes on the affected machine. The behavior of the malware may vary depending on the downloaded code.

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.438.08

FIRST VSAPI PATTERN DATE:

30 May 2017

VSAPI OPR PATTERN File:

13.439.00

VSAPI OPR PATTERN Date:

31 May 2017

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

Search and delete this file

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.  %User Profile%\Downloads\awareness.doc
%User Profile%\Downloads\update.vbs
%User Startup%\start.vbs

Step 3

Restart in normal mode and scan your computer with your Trend Micro product for files detected as X2KM_DLOADER.JK. 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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