DeadLock Ransomware Using Polygon Smart Contracts to Evade Detection

The DeadLock ransomware group has adopted a sophisticated new technique to enhance operational resilience and evade traditional cybersecurity detection methods by leveraging the Polygon (MATIC) blockchain. This approach marks a significant evolution in ransomware C2 (Command and Control) infrastructure.

The core innovation lies in utilizing Polygon smart contracts—typically deployed for decentralized finance (DeFi) applications—to host critical operational data. Instead of relying on traditional web infrastructure (IP addresses, Tor domains, or dedicated servers) which can be seized or blocklisted by security researchers and law enforcement, DeadLock attackers store instructions, payment verification status, decryption keys, and victim-specific identifiers within the immutable ledger of the Polygon network.

This method offers two major advantages to the attackers. First, the smart contract is decentralized and virtually impossible to take down without compromising the entire blockchain network. Second, communications with the contract bypass standard network monitoring solutions. Security appliances that typically flag known malicious IPs or monitor anomalous C2 traffic see only legitimate HTTPS calls directed at public Polygon nodes or RPC providers (Remote Procedure Call). The true C2 data is hidden within transaction inputs or contract event logs, masking the malicious intent.

If a victim pays the ransom, the transaction updates the status on the smart contract. The victim’s decryption tool then queries the contract for proof of payment, retrieves the corresponding decryption key stored in a subsequent transaction, and proceeds with file recovery. This shift transforms monitoring an endpoint attack into monitoring a complex, multi-chain financial ledger, significantly raising the bar for threat detection and response teams.

Source: DeadLock Ransomware Using Polygon Smart Contracts to Evade Detection