Analysis by: Clive Fuentebella
 Modified by: Patrick Noel Collado
 PLATFORM:

Windows

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

  • Threat Type: Trojan Spy

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

This Trojan Spy 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: 6,270,976 bytes
File Type: EXE
File Compression: Themida
Memory Resident: No
Initial Samples Received Date: 03 Nov 2021
Payload: Connects to URLs/IPs, Uploads files

Arrival Details

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

Installation

This Trojan Spy adds the following processes:

  • powershell.exe -WindowStyle Hidden -C $path = '" %Malware Path% "';Get-Process | Where-Object {$_.Path -like $path} | Stop-Process -Force;[byte[]]$arr = new-object byte[] 65536;Set-Content -Path $path -Value $arr;Remove-Item -Path $path

Information Theft

This Trojan Spy accepts the following parameters:

  • nownd or -nownd → executes itself with its window hidden.
  • exists or -exists → checks if file exists

Other Details

This Trojan Spy does the following:

  • Sends files to the following URL:
    • https://{BLOCKED}.{BLOCKED}.17.114/data/
    • Then it creates a directory in the URL where it saves the stolen files
  • It takes ownership of its executable folder and removes all other account’s access
  • The files it sends must be from 1 year ago up to 6 years ago from its execution date
  • The files it sends must be from 6 months ago up to 10 years from its execution date
  • It does not send system files, temporary files, and directories
  • It does not send files smaller than 1024 bytes
  • It does not send files with the following file mask:
    • OneDriveMedTile
    • locale-
    • SmallLogo
    • VisualElements
    • adobe_sign
    • Adobe Sign
    • core_icons
  • It does not send files from the following directories:
    • C:\Documents and Settings
    • C:\PerfLogs
    • C:\Program Files\Windows Defender Advanced Threat Protection
    • C:\Program Files\WindowsApps
    • C:\ProgramData\Application Data
    • C:\ProgramData\Desktop
    • C:\ProgramData\Documents
    • C:\ProgramData\Microsoft
    • C:\ProgramData\Packages
    • C:\ProgramData\Start Menu
    • C:\ProgramData\Templates
    • C:\ProgramData\WindowsHolographicDevices
    • C:\Recovery
    • C:\System Volume Information
    • C:\Users\All Users
    • C:\Users\Default
    • C:\Users\Public\Documents
    • C:\Windows
    • System Volume Information
  • It uploads files with the following extensions:
    • .doc
    • .docx
    • .xls
    • .xlsx
    • .xlsm
    • .pdf
    • .msg
    • .ppt
    • .pptx
    • .sda
    • .sdm
    • .sdw
    • .csv
    • .zip
    • .json
    • .config
    • .ts
    • .cs
    • .sqlite
    • .aspx
    • .pst

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 17.170.05
FIRST VSAPI PATTERN DATE: 03 Nov 2021
VSAPI OPR PATTERN File: 17.171.00
VSAPI OPR PATTERN Date: 04 Nov 2021

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

Identify and terminate files detected as TrojanSpy.Win32.EXMATTER.YPBKC

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 4

Scan your computer with your Trend Micro product to delete files detected as TrojanSpy.Win32.EXMATTER.YPBKC. 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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