Aeternum C2 Leverages Polygon Blockchain for Command-and-Control

Aeternum C2 represents a sophisticated evolution in botnet architecture by abandoning traditional domain-based command-and-control (C2) mechanisms in favor of decentralized ledger technology. According to The Hacker News, researchers at Qrator Labs have identified this new loader utilizing the Polygon blockchain to host encrypted operational instructions. This tactical shift provides the botnet with an unprecedented level of resilience against standard defensive measures such as DNS sinkholing, domain seizures, and IP-based blacklisting.

Technical Analysis of Blockchain-Based C2

Traditional malware infrastructures rely on a centralized server or a set of domains to issue commands to infected hosts. While techniques like Domain Generation Algorithms (DGA) have historically increased resilience, they remain vulnerable to takedowns by registrars or law enforcement. Aeternum C2 bypasses these vulnerabilities by leveraging the Polygon network’s immutable and decentralized nature.

Command Retrieval and Execution

The loader is programmed to query the Polygon blockchain—specifically targeting a predefined wallet address or smart contract—to retrieve transaction data. This data contains the encrypted commands for the botnet. Because these instructions reside on a public blockchain, they cannot be deleted or modified by third parties. To execute a change in the botnet’s behavior, the threat actor simply initiates a new transaction on the Polygon network containing the updated, encrypted payload.

Encryption and Obfuscation

To prevent security researchers from easily monitoring the botnet’s activities, the commands stored on the blockchain are encrypted. This means that even though the transaction data is public, the specific intent of the command—such as downloading a secondary payload, exfiltrating data, or launching a DDoS attack—remains hidden. Sandboxes and automated traffic analysis tools may observe the connection to the blockchain infrastructure but will fail to interpret the malicious instructions without the decryption key embedded within the malware sample.

The Strategic Advantage of Polygon

The choice of the Polygon blockchain over others, such as Bitcoin or Ethereum, is likely driven by operational costs. Polygon is a Layer-2 scaling solution known for significantly lower transaction fees (gas fees) and faster block times. For a threat actor, this allows for the frequent updating of commands and the maintenance of a large-scale botnet at a negligible cost, making the infrastructure both economically viable and technically robust.

Detection and Mitigation Challenges

Detecting Aeternum C2 presents significant challenges for network defenders. Most enterprise environments do not block traffic to blockchain infrastructure, as it is often used for legitimate business applications or by authorized decentralized applications (dApps).

Identification Obstacles

1. Legitimate Traffic Masking: The malware often communicates with the blockchain via public Remote Procedure Call (RPC) nodes or API providers like Infura and Alchemy. Blocking these services can lead to significant false positives and business disruption.
2. Lack of Takedown Mechanism: Since no central authority controls the Polygon network, there is no single entity that can be served with a legal order to remove the malicious commands.

Defensive Recommendations

Defenders should prioritize host-based detection and behavioral analysis to identify the initial infection vector.

• Endpoint Detection and Response (EDR): Focus on identifying the loader’s execution, memory injection techniques, and persistence mechanisms on the host rather than relying solely on network-level indicators.
• Traffic Baselining: Monitor for unusual volumes of traffic directed toward blockchain RPC endpoints, especially from workstations that have no legitimate business need to interact with decentralized ledgers.
• Protocol Inspection: Use Deep Packet Inspection (DPI) to identify unusual patterns in the payload of requests sent to blockchain APIs, even if the destination is a reputable provider.