Security Threats

What is malware?
(*Remember to always give an example in these types of questions!*)

What is the job of anti-virus software? What does it contain?

What does a virus has that makes it available to be scanned by a real-time scanner?

What is the purpose of anti-malware software?
(*Remember to have available examples!*)

What is a backdoor? What can a hacker do when they have a backdoor?

How does a firewall defend a computer from malware?
(*Think of it in steps!*)