WORMS:
A computer worm is a subset of the Trojan horse malware that can propagate or self-replicate from one computer to another without human activation after breaching a system. Typically, a worm spreads across a network through your Internet or LAN (Local Area Network) connection. Naturally, you must be wondering what is a Trojan and how does it relate to computer worms?To keep it brief, a Trojan uses trickery and social engineering to deceive people into running it. For example, a Trojan may pretend to be legitimate software. A worm is a type of Trojan because it normally relies on social engineering to attack systems.
Viruses:
A computer virus is a type of malware that attaches to another program (like a document), which can replicate and spread after a person first runs it on their system. For instance, you could receive an email with a malicious attachment, open the file unknowingly, and then the computer virus runs on your computer. Viruses are harmful and can destroy data, slow down system resources, and log keystrokes.Cybercriminals aren’t creating new viruses all the time, instead they focus their efforts on more sophisticated and lucrative threats. When people talk about “getting a virus” on their computer, they usually mean some form of malware—it could be a virus, computer worm, Trojan, ransomware or some other harmful thing. Viruses and malware continue to evolve, and often cybercriminals use the type that gives them the best return at that particular time.
Bots:
A bot -- short for robot and also called an internet bot -- is a computer program that operates as an agent for a user or other program or to simulate a human activity. Bots are normally used to automate certain tasks, meaning they can run without specific instructions from humans.An organization or individual can use a bot to replace a repetitive task that a human would otherwise have to perform. Bots are also much faster at these tasks than humans. Although bots can carry out useful functions, they can also be malicious and come in the form of malware.
