Adam, a malicious hacker, wants to perform a reliable scan against a remote target. He is not concerned about being stealth at this point. Which of the following type of scans would be most accurate…

UDP scans are inherently unreliable because UDP is connectionless and dropped packets produce no response, making it difficult to distinguish open ports from filtered ones.

TCP Connect scan completes the full TCP three-way handshake (SYN, SYN-ACK, ACK) with the target port, receiving a definitive open or closed response. Because the OS completes the connection, the result is highly reliable and accurate. It is easily detected and logged, but that is acceptable when reliability is the priority.

ACK scans do not determine whether a port is open or closed - they are used to map firewall rulesets by observing RST responses, not to confirm service availability.

FIN scans are stealth techniques that exploit TCP behavior in some OSes to infer port state, but they are unreliable because many modern systems do not respond as expected.