Ethical Hacking Essentials 2025 – 400 Free Practice Questions to Pass the Exam

The Sybil attack is characterized by an attacker creating multiple forged identities, often to manipulate the perception of the system's state. In a Sybil attack, the malicious actor can produce numerous fake nodes that participate in the network, which can mislead genuine nodes. By generating a sense of traffic congestion or false data, the attacker can significantly influence the network's decision-making processes or create vulnerabilities for exploitation.

This form of attack is particularly relevant in peer-to-peer networks and blockchain technologies, where trust and consensus are crucial. By pretending to be multiple different users, the attacker can disrupt normal operations or gain undue influence in the network, which can lead to additional attacks or data manipulation.

The other options, while related to networking and security, involve different mechanics: a Replay attack focuses on reusing valid commands to trick a system, a Denial of Service attack aims to overwhelm a service with traffic to make it unavailable, and a Data injection attack involves inserting malicious data to manipulate systems or applications. Each of these attacks has distinct characteristics and methods of execution that differentiate them from a Sybil attack.