Sam is a penetration tester hired by Inception Tech, a security organization. He was asked to perform port scanning on a target host in the network. While performing the given task, Sam sends FIN/ACK probes and determines that an RST packet is sent in response by the target host, indicating that the port is closed.
What is the port scanning technique used by Sam to discover open ports?
Correct Answer: C
TCP Maimon scan
This scan technique is very similar to NULL, FIN, and Xmas scan, but the probe used here is FIN/ACK. In most cases, to determine if the port is open or closed, the RST packet should be generated as a response to a probe request. However, in many BSD systems, the port is open if the packet gets dropped in response to a probe.
https://nmap.org/book/scan-methods-maimon-scan.html
How Nmap interprets responses to a Maimon scan probe
Probe Response Assigned State
No response received (even after retransmissions) open|filtered
TCP RST packet closed
ICMP unreachable error (type 3, code 1, 2, 3, 9, 10, or 13) filtered