Analysis by: Jennifer Gumban
 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, Downloaded from the Internet

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

It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system. As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 73,284 bytes
File Type: DOCX
Memory Resident: No
Initial Samples Received Date: 11 May 2017
Payload: Connects to URLs/IPs, Downloads files

Arrival Details

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

It may be dropped by other malware.

This malware arrives via the following means:

  • As an embedded file in a PDF file.

Download Routine

This Trojan accesses the following websites to download files:

  • http://{BLOCKED}.{BLOCKED}.139.23:80/f87346b
  • http://{BLOCKED}kar.ru/f87346b
  • http://{BLOCKED}17.com/f87346b
  • http://{BLOCKED}4fffrottd.com/af/f87346b
  • http://{BLOCKED}fg43ff4f.net/af/f87346b

It saves the files it downloads using the following names:

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

As of this writing, the said sites are inaccessible.

Other Details

This is the Trend Micro detection for Microsoft Word documents that are compromised through the insertion of a malicious macro.

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.398.02
FIRST VSAPI PATTERN DATE: 11 May 2017
VSAPI OPR PATTERN File: 13.399.00
VSAPI OPR PATTERN Date: 12 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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Remove malware/grayware files dropped/downloaded by W2KM_DLOADR.YYTAB. (Note: Please skip this step if the threats listed below have already been removed.)

     
    • Ransom_CRYPJAFF.B

Step 4

Scan your computer with your Trend Micro product to delete files detected as W2KM_DLOADR.YYTAB. 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.


Did this description help? Tell us how we did.