_________________ is a program that covertly searches individual packets of data as they pass through the Internet, capturing passwords or the entire contents.

Answer: Option D

Packet Sniffer is a program that covertly searches individual packets of data as they pass through the Internet, capturing passwords or the entire contents. A packet analyzer (also known as a packet sniffer) is a computer program or piece of computer hardware (such as a packet capture appliance) that can intercept and log traffic that passes over a digital network or part of a network.