A penetration tester wants to perform reconnaissance without being detected. Which of the following activities have a MINIMAL chance of detection? (Choose two.)

Open-source research (OSINT) involves gathering publicly available information from sources like websites, social media, and public records, which generates no traffic to the target system and therefore has a minimal chance of detection. This is a purely passive reconnaissance technique.

A ping sweep sends ICMP echo requests to multiple hosts, which generates active network traffic and can be easily detected by network monitoring systems.

Traffic sniffing (passive listening) on a network segment, where the penetration tester is already present and configured to capture packets without sending any active probes, has a minimal chance of detection from the target, as no direct interaction or unusual network activity is initiated from the attacker's side.

Port knocking involves sending specific, ordered connection attempts to closed ports to open another port, which is an active and distinct network pattern that can be detected.

A vulnerability scan involves sending numerous probes and tests to systems to identify weaknesses, generating significant active network traffic and often triggering alerts in intrusion detection systems (IDS).

An Nmap scan sends various types of packets to discover hosts and open ports, creating distinct network footprints that can be detected and logged by firewalls and IDS.