30: Cybersecurity Practitioner What are worms? A O An exploit of a network infrastructure device vulnerability that installs a backdoor on the affected system. B O Viruses that replicate themselves over the network, infecting numerous vulnerable systems. On most occasions, a worm will execute malicious instructions on a remote system without user interaction. CO A type of malware that compromises a system and then often demands a ransom from the victim to pay the attacker in order for the malicious activity to cease or for the malware to be removed from the affected system. D O An exploit of a firewall vulnerability that installs a backdoor on the affected system