What are the different types of infections and virus. What are the differences
This is one of the most common phrases used when talking about a virus. Trojan comes from the Trojan Horse that contained something that you did not want or expect. This is why it is named as such because it is a program that you think you want to use that contains an infection that it will put onto your computer
Malware is malicious software. Just like the term virus, malware is generally used as a catch all term. Malware can cover many things including viruses, trojans, rootkits, worms, spyware and PUP (Potentially Unwanted Programs).
A worm is a program that self-replicates. This means that without the user needing to do anything it will copy its self, which can be ataching to things like emails. This allows it to spread very quickly especially inside a network.
Spyware is a malicious infection that is built to remove information from a computer. This can be passwords, bank details or just monitoring everything you do on your computer. It is generally made to try to stay hidden, which can be done by changing your computers settings.
Ransomeware is designed to take money from you. It will lock up your computer, remove features from your computer or try to scare you into paying. They tend to act as an antivirus that has found lots of infections but needs payment to remove them or as a government or police notice that you have been doing something illegal and need to pay a fine. Others more reciently have been encrypting your files to demand you to buy the password. (Cryptolocker)
A rootkit is a program that hides other infections. It takes over settings, changes files around and creates backdoors to allow easier access for the hacker or to allow other infections easy access.