Analysis by: Arvin Roi Macaraeg
ALIASES:

Trojan-Downloader.MSExcel.Agent.kh(Kaspersky); TrojanDownloader:O97M/Donoff(Microsoft); VBA/TrojanDownloader.Agent.NKZ(ESET-NOD32)

 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: Dropped by other malware, Downloaded from the Internet, Spammed via email

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.

However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 95,232 bytes
File Type: XLS
Memory Resident: Yes
Initial Samples Received Date: 03 Apr 2019
Payload: Displays graphics/image, Connects to URLs/IPs

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.

Other Details

This Trojan does the following:

  • Drops the following file as a copy of "POWERSHELL.exe":
    • %User Profile%\{random capital leters}\{random capital leters}.EXE
  • It connects to the following URL to download and execute codes to its memory:
    • https://{BLOCKED}an.com/uploads/changed.pdf
  • The document contains the following message details luring users to enable macro content:

However, as of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.916.03
FIRST VSAPI PATTERN DATE: 03 Apr 2019
VSAPI OPR PATTERN File: 14.917.00
VSAPI OPR PATTERN Date: 04 Apr 2019

Step 1

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 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

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 Profile%\{random capital leters}\{random capital leters}.EXE

Step 4

Search and delete this folder

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.  
  • %User Profile%\{random capital leters}

Step 5

Scan your computer with your Trend Micro product to delete files detected as Trojan.X97M.DLOADR.JHKT. 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:


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