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Trojan.JS.CRYXOS.QUSMANGAGBS

December 06, 2022
 Analysis by: Carlos Villegas Madrid
 ALIASES:

JS:Dropper-AAFB [Trj] (AVAST)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW


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:

261,935 bytes

File Type:

JS

Memory Resident:

No

Initial Samples Received Date:

02 Dec 2022

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.

Installation

This Trojan adds the following processes:

  • "%System%\WScript.exe" "{Malware Path}\{Malware File Name}"

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

Other Details

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\XFDejZ

It connects to the following possibly malicious URL:

  • www.{BLOCKED}on-atelier-garage.com
  • ctldl.{BLOCKED}supdate.com
  • www.{BLOCKED}s.dk

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

18.108.08

FIRST VSAPI PATTERN DATE:

02 Dec 2022

VSAPI OPR PATTERN File:

18.109.00

VSAPI OPR PATTERN Date:

03 Dec 2022

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

     
    • Downloader.JS.TRX.XXJSE9EFF041

Step 2

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 3

Delete this registry key

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\XFDejZ

Step 4

Scan your computer with your Trend Micro product to delete files detected as Trojan.JS.CRYXOS.QUSMANGAGBS. 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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