Which type of malicious program is self-replicating and does not require a host program?

A worm is a type of malicious program that is designed to self-replicate and propagate across networks and systems without the need for a host program. Unlike viruses, which attach themselves to legitimate applications or files to spread, worms are standalone programs that exploit vulnerabilities in networking protocols or software to create copies of themselves in different locations. This ability to replicate independently allows worms to spread rapidly, often resulting in significant harm to networks and systems.

In the context of malware, worms can cause network congestion, may lead to system resource depletion, and can be part of larger attacks that aim to deliver payloads such as ransomware or other types of malicious software. Their self-sufficient nature sets them apart from other types of malicious programs, highlighting their capacity for autonomous movement through networks, which can make them particularly dangerous.