Which activity would NOT be considered passive footprinting?

Passive footprinting refers to the process of collecting information about a target without directly engaging with the target's systems. This approach generally relies on publicly available resources and information that can be accessed without alerting the target.

Using network scanning tools indicates active engagement with the target's systems to retrieve information. This method involves sending packets to the target and analyzing the responses, which creates a potential risk of detection as it interacts directly with the network. This active approach distinguishes it from techniques like gathering information from social media, reviewing public records, or checking domain registration details, all of which involve collecting existing information without any direct interaction with the target’s systems.

The other activities mentioned rely on leveraging accessible information sources that do not alert the target, thereby fitting squarely within the definition of passive footprinting. Gathering information from social media can reveal insights about the individuals associated with the target, while public records and domain registration details provide valuable background without any inquiry that could be traced back to the requester.