Final answer:
Anonymous is a loosely organized group of hacktivists noted for cyber attacks on government and corporate entities, notably during the Arab Spring. A program that autonomously spreads through networks exploiting security holes is known as a worm.
Step-by-step explanation:
Anonymous is b) a loosely organized group of hacktivists that claimed responsibility for a DDoS attack on Church of Scientology Web sites. They are known for their involvement in high-profile online protests and cyber attacks against government institutions and corporations. Anonymous gained attention for initiating “Operation Egypt”, where they attacked Egyptian government websites and sent thousands of faxes amid the Arab Spring when the government shut down the Internet to curb social movements.
A self-contained program that spreads through a computer network by exploiting security holes is called a worm. This program operates without the need for user intervention and can cause disruption by exploiting vulnerabilities in network software.