Denial-of-Service (DoS) attack: an attempt to make a machine or network resource unavailable to those attempting to reach it.
Distributed denial-of-service (DDoS) attack:Multitude systems attack a single target, therebycausing denial of service for users of the targetedsystem
Phishing/Spear Phishing: Spear phishing is an e-mail spoofing fraud attempt that targets a specificorganization, seeking unauthorized access toconfidential data
Social Engineering- Con game For example, call the authorized employee with some kind of urgent problem that requires immediate network access.
Impersonation attack: is an attack in which an adversary successfully assumes the identity of one of the legitimate parties in a system or in a communications protocol
Man in the middle attack: The attacker makes independent connection with the victims and relay messages between them, making them believe thatthey are talking directly to each other over a privateconnection(Usually in cryptography)
Spoofing: is when a malicious party impersonateanother device or user on a network in order to launch attacks against network hosts, steal data,spread malware, or bypass access controls (IPaddress spoofing).