W2KM_LOCKY.DLDVFY

December 05, 2016
 Analysis by: John Kevin Sanchez
 ALIASES:

TrojanDownloader:O97M/Donoff (Microsoft), W97M/Downloader.bni (McAfee), WM/Agent.8A76!tr (Fortinet)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware, Downloaded from the Internet

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size:

32,123 bytes

File Type:

DOC

Memory Resident:

No

Initial Samples Received Date:

30 Nov 2016

Payload:

Downloads files, Executes files

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Download Routine

This Trojan connects to the following website(s) to download and execute a malicious file:

  • http://{BLOCKED}toshopping.com.ar/873nf3g

It saves the files it downloads using the following names:

  • %User Temp%\herpack1 - encrypted downloaded file
  • %User Temp%\ajufr51.dll

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Trend Micro detects the dowloaded file as:

  • Ransom_LOCKY.DLDTAQW

Other Details

This Trojan does the following:

  • It executes the downloaded file using the following command:
    rundll32.exe %User Temp%\ajufr51.dll,init_data

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

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

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

12.930.06

FIRST VSAPI PATTERN DATE:

30 Nov 2016

VSAPI OPR PATTERN File:

12.931.00

VSAPI OPR PATTERN Date:

01 Dec 2016

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 the malware/grayware file dropped/downloaded by W2KM_LOCKY.DLDVFY. (Note: Please skip this step if the threat(s) listed below have already been removed.)

    • Ransom_LOCKY.DLDTAQW

Step 4

Search and delete these files

[ 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 Temp%\herpack1

Step 5

Scan your computer with your Trend Micro product to delete files detected as W2KM_LOCKY.DLDVFY. 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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