Final answer:
Examples of network security attacks include replay, masquerade, message modification, and denial of service. These are intentional actions aimed at compromising the integrity, confidentiality, and availability of network resources.
Step-by-step explanation:
Replay, masquerade, modification of messages, and denial of service are examples of network security attacks. These attacks are designed to disrupt the normal functioning of a network, intercept sensitive information, or pose as another user to gain unauthorized access. Replay attacks involve capturing a data transmission and retransmitting it to create an unauthorized effect. Masquerade attacks occur when an attacker pretends to be someone else to gain access. Modification of messages is altering the communication between two parties without their knowledge. Finally, denial of service (DoS) attacks aim to make a network resource unavailable to its intended users by overwhelming it with superfluous requests.