Menu

  • Alerts
  • Incidents
  • News
  • APTs
  • Cyber Decoded
  • Cyber Hygiene
  • Cyber Review
  • Cyber Tips
  • Definitions
  • Malware
  • Threat Actors
  • Tutorials

Useful Tools

  • Password generator
  • Report an incident
  • Report to authorities
No Result
View All Result
CTF Hack Havoc
CyberMaterial
  • Education
    • Cyber Decoded
    • Definitions
  • Information
    • Alerts
    • Incidents
    • News
  • Insights
    • Cyber Hygiene
    • Cyber Review
    • Tips
    • Tutorials
  • Support
    • Contact Us
    • Report an incident
  • About
    • About Us
    • Advertise with us
Get Help
Hall of Hacks
  • Education
    • Cyber Decoded
    • Definitions
  • Information
    • Alerts
    • Incidents
    • News
  • Insights
    • Cyber Hygiene
    • Cyber Review
    • Tips
    • Tutorials
  • Support
    • Contact Us
    • Report an incident
  • About
    • About Us
    • Advertise with us
Get Help
No Result
View All Result
Hall of Hacks
CyberMaterial
No Result
View All Result
Home Alerts

Monti Ransomware Strategy Shift

August 15, 2023
Reading Time: 2 mins read
in Alerts
Monti Ransomware Strategy Shift

The Monti ransomware, known for its dual Windows and Linux-based variants, garnered attention in June 2022 due to its uncanny resemblance to the notorious Conti ransomware. This not only included a shared name but also replicated tactics and techniques employed by Conti. Operating under the moniker “Monti,” the group intentionally adopted Conti’s methods, incorporating a significant portion of their tools and even utilizing leaked Conti source code.

Having continuously targeted various companies since its discovery, the Monti group recently recommenced its malicious activities, focusing on legal and governmental sectors. Simultaneously, a fresh Linux-based variant of Monti (Ransom.Linux.MONTI.THGOCBC) has surfaced, displaying substantial deviations from its predecessors, particularly in its choice of encryptor and additional behaviors. It’s noteworthy that only three security vendors flagged the sample as malicious on VirusTotal as of the current writing.

Comparing the newly emerged Linux variant to its older counterpart using BinDiff, a similarity rate of 29% was revealed, in stark contrast to the 99% similarity rate shared among older variants and Conti ransomware. An analysis of the new Linux variant uncovered distinct changes in its command line arguments, incorporating new parameters and omitting others from its predecessor.

Notably, this version employs the -type=soft parameter, indicative of a strategy to reduce immediate detection risks while executing activities, as opposed to the earlier –type=hard parameter. The Monti group’s manipulation of key files such as /etc/motd and index.html replaces their contents with ransom notes, notifying victims of successful server infiltration. Among the additions in this new variant is an “infection marker” consisting of appended bytes “MONTI” followed by an additional 256 bytes linked to the encryption key.

Further investigation revealed the malware’s file size-based encryption process, differing from the earlier variant’s use of a –size argument. This new variant solely relies on the file size for encryption determination, with the ransomware encrypting files differently based on their size. Notably, files exceeding 4.19MB employ a Shift Right operation to calculate total encryption size, while files smaller than 1.048MB have all their content encrypted. The new version continues the trend of appending the .monti extension to encrypted files and distributing its ransom note readme.txt throughout directories.

An interesting discovery during sample analysis was a decryption code, suggesting testing of functionality by the threat actor. However, this code remains ineffective without the private key known only to the malware author, having no connection to the malware’s routine.

In conclusion, while evidence suggests that Monti’s operators integrated portions of Conti’s source code as the foundation for this new variant, significant modifications have been made, especially to the encryption algorithm. This strategic shift enhances the malware’s ability to evade detection, posing a greater challenge for identification and mitigation.

To protect against such ransomware attacks, organizations are strongly advised to adopt robust defense strategies encompassing data safeguarding protocols, along with comprehensive backup and recovery procedures, ensuring data security and potential restoration in the face of encryption or deletion threats.

Reference:
  • Monti Ransomware Unleashes a New Encryptor for Linux
Tags: August 2023Cyber AlertCyber Alerts 2023CyberattackCybersecurityLinuxMontiMonti ransomwareRansomwareVulnerabilitiesWindows
ADVERTISEMENT

Related Posts

Glibc Flaw Gives Linux Root Access Risk

Mozilla Urgent Firefox Patch Fixes RCE Flaws

May 19, 2025
Fileless Remcos RAT Delivery Via LNK Files

ModiLoader Malware Targets Windows Users

May 19, 2025
Glibc Flaw Gives Linux Root Access Risk

Glibc Flaw Gives Linux Root Access Risk

May 19, 2025
Fileless Remcos RAT Delivery Via LNK Files

APT28 RoundPress Webmail Hack Steals Emails

May 16, 2025
Fileless Remcos RAT Delivery Via LNK Files

FBI Warns of AI Voice Phishing Scams

May 16, 2025
Fileless Remcos RAT Delivery Via LNK Files

Fileless Remcos RAT Delivery Via LNK Files

May 16, 2025

Latest Alerts

Mozilla Urgent Firefox Patch Fixes RCE Flaws

ModiLoader Malware Targets Windows Users

Glibc Flaw Gives Linux Root Access Risk

Fileless Remcos RAT Delivery Via LNK Files

FBI Warns of AI Voice Phishing Scams

APT28 RoundPress Webmail Hack Steals Emails

Subscribe to our newsletter

    Latest Incidents

    Massive DDoS Hits Poland’s Civic Platform

    Arla Plant Cyberattack Halts Operations

    Georgia’s Harbin Clinic Hit by Data Breach

    Hackers Target Swiss Reserve Power Plant

    Coinbase Insider Attack Exposed User Data

    Cyberattack Hits J Batista Group

    CyberMaterial Logo
    • About Us
    • Contact Us
    • Jobs
    • Legal and Privacy Policy
    • Site Map

    © 2025 | CyberMaterial | All rights reserved

    Welcome Back!

    Login to your account below

    Forgotten Password?

    Retrieve your password

    Please enter your username or email address to reset your password.

    Log In

    Add New Playlist

    No Result
    View All Result
    • Alerts
    • Incidents
    • News
    • Cyber Decoded
    • Cyber Hygiene
    • Cyber Review
    • Definitions
    • Malware
    • Cyber Tips
    • Tutorials
    • Advanced Persistent Threats
    • Threat Actors
    • Report an incident
    • Password Generator
    • About Us
    • Contact Us
    • Advertise with us

    Copyright © 2025 CyberMaterial