Network security

Question 1

What are examples of external threats?

Answer 1

Viruses ,worms and Trojan horses.
Spyware and adware
zero day attacks
threat actor attacks (hackers)
Denial of service attacks 
data interception and theft. 
identity theft.

Question 2

What are some examples of internal threats?

Answer 2

Lost or stolen devices.
Accidental misuse by employees.
malicious employees.

Question 3

How can security be implanted?

Answer 3

Antivirus and antispyware.
Firewall filtering
Dedicated firewall systems
Access control lists(ACL)
Intrusion prevention systems(IPS)
Virtual Private networks(VPNs)