A virus or worm can have a payload that installs a(n) door or trap-door component in a system, which allows the attacker to access the system at will with special privileges.

backdoor or trapdoor

Explanation:

A backdoor is also known as a trapdoor or manhole and is known to be a secret means of bypassing security in order to gain access to a system or a restricted part of a system. Some virus contains payload that installs a backdoor component in a system. This backdoor, thus grants the attacker special privilege access to the system at anytime.

Back

Explanation:

Cyber attackers are individuals with networking and hacking skills needed to exploit vulnerabilities in networks to retrieve and steal information for mischievous reasons.

Malicious softwares or malwares are program softwares developed and planted to infiltrate system and network security. Examples of malwares are virus, worm, rootkit, Trojan horse, keylogger etc. They infect systems and networks to creat a back or trap door or loophole for attackers to access networks.

i want to say d but i could be wrong however it is organized if that could happen..

hope it could

b. xor is the correct answer