Silent Infection: Local Keys and USB Schemes
Security experts have uncovered a disturbing escalation in ransomware tactics: Mamona. This new malware executes entirely offline, encrypting files on compromised Windows systems without contacting any remote servers. Instead, it abuses the built-in ping command to initiate encryption, allowing it to evade conventional network-based detection systems.
“Mamona generates encryption keys locally, making it effective even in air-gapped or isolated systems, challenging the belief that offline environments are inherently secure,” explained Neehar Pathare, MD of 63SATS Cybertech. “This approach allows attackers to bypass standard network surveillance, making detection difficult.”
The attack typically unfolds when a user inserts a contaminated USB device or external hard drive. Hidden files, autorun scripts, and obfuscated executables carry the ransomware into air-gapped PCs. Upon execution, Mamona quietly begins encrypting documents, pictures, and data before displaying a ransom demand, often via a QR code or email instructions to a secondary device like a smartphone.
Why Mamona Threatens “Secure” Networks
Offline malware like Mamona represents a seismic shift in threat modelling for organisations that rely on isolated infrastructure:
No network traffic needed: Traditional endpoint or IDS systems may miss the threat completely.
Old software vulnerabilities: Offline machines often lag in updates, providing an easy entry point.
Delayed detection: Users may not notice encrypted files until hours or days after infection.
Unrestricted physical entry: USB ports are often poorly monitored, making malware delivery simple.
“Everything Mamona needs to lock your files is built into the malware itself. Once executed, it begins encrypting data autonomously, without needing to contact any server or hacker,” said cybersecurity expert Shubham Singh.
How to Defend Against Mamona
To guard against this stealthy threat, organisations must adopt a multi-layered defence approach:
Ban unknown USBs: Prohibit USB drives from unverified sources.
Use offline-capable endpoint protection: Deploy antivirus solutions that scan locally.
Apply firmware and OS patches: Even air-gapped systems need periodic updates.
Maintain cold backups: Store critical data in write-protected, offline formats.
Monitor for anomalies: Watch for unauthorised file renaming or inaccessible documents.
Educate staff: Reinforce cautious handling of physical media.
“Hardware-based allow‑listing and strong endpoint monitoring are critical in defending isolated systems,” Pathare added.
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The Takeaway
Mamona’s arrival is a stark reminder that offline systems are no longer immune to cyber threats. Organisations must pivot from a network-centric security mindset to a holistic “physical-and-digital” model, placing equal weight on endpoint control, policy enforcement, and user training in offline environments.