In decentralized networks, particularly those based on blockchain technology, nodes are participants that maintain the network by validating transactions and ensuring consensus. A malicious node operates with intent to harm the network or its participants. This may involve tactics such as double-spending attacks, creating forks to disrupt consensus, or launching distributed denial-of-service (DDoS) attacks to overwhelm and incapacitate other nodes. Malicious nodes can undermine the integrity of the network by spreading false information or invalid transactions.