Analysis by: Paul Steven Nadera
ALIASES:

Trojan:JS/Nemucod!MSR (Microsoft); Trojan.JS.Cryxos (Ikarus); JS/Cryxos.1952!tr (Fortinet)

 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: Downloaded from the Internet, Dropped by other malware

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.

As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 56,789 bytes
File Type: HTML, HTM
Memory Resident: No
Initial Samples Received Date: 29 May 2020
Payload: Connects to URLs/IPs, Downloads 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

As of this writing, the said sites are inaccessible.

Other Details

This Trojan does the following:

  • It connects to the following website(s) to download and execute a malicious script:
    • http://{BLOCKED}.{BLOCKED}.177.85/5cw2fk

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 15.898.02
FIRST VSAPI PATTERN DATE: 29 May 2020
VSAPI OPR PATTERN File: 15.899.00
VSAPI OPR PATTERN Date: 30 May 2020

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

Scan your computer with your Trend Micro product to delete files detected as Trojan.HTML.NEMUCOD.EB. 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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