In order to coordinate the activity of many infected computers, attackers have used coordinating
systems known as:

A.
wormnets

B.
trojannets

C.
spynets

D.
botnets

E.
rootnets

F.
backdoor

Explanation:
In order to coordinate the activity of many infected computers, attackers ave used coordinating
systems known as botnets. In a botnet, the malware or malbot logs in to an Internet Relay Chat
channel or other chat system. The attacker can then give instructions to all the infected systems
simultaneously.