Which of the following is NOT an example of passive footprinting?

Scanning ports requires sending probe packets directly to the target host to determine which services are listening, which constitutes active reconnaissance. This direct interaction with the target distinguishes it from passive techniques, where the attacker gathers publicly available data without ever contacting or alerting the target system.

Analyzing job requirements is passive footprinting because it involves reviewing publicly posted information such as job listings to infer the target organization's technology stack and infrastructure without any direct contact.

Performing a whois query is passive footprinting because it retrieves publicly registered domain, IP block, and registrant information from third-party registries without probing the target directly.

Querying a search engine is passive footprinting because it leverages publicly indexed data to gather information about a target without establishing any direct connection to the target's systems.