Types of malware

 Types of malware 

What is malware? 

Malware (malicious software) is computer code created by hackers to cause harm to a computer/computer system. There are many different types of malware each with its own unique properties. 

Adware 

Adware is malicious code that involuntarily shows adverts on a victim’s PC. These adverts are usually in the style of pop-ups. Adware can also inject itself into regular applications to infect them and cause adverts to pop-up whilst using them. Adware is relatively harmless however; they are often infected with spyware and keyloggers. 

Keylogger 

A keylogger is a program written to record keystrokes and log them in a text file. This file can either be remotely accessed by the hacker or physically accessed by logging onto the infected PC and recording the contents. Keyloggers record keystrokes which the user makes which could reveal sensitive information such as emails, passwords, phone numbers, etc... 

Trojan 

A trojan horse virus is a type of malware that socially engineers the victim into installing it thinking it is a real product. Trojans are named after the mythological trojan horse in the Trojan-Greek war. The Greeks used a giant wooden horse to sneak into the city of Troy undetected. This is how the Trojan malware got its name. 

Remote access trojan (RAT) 

RATs are installed without the victim’s knowledge and allow the hacker to remotely access their PC without their knowledge. This allows the hacker to steal information, spread the virus, and harm the PC. 

Ransomware 

Ransomware is a virus that when installed, encrypts all the victim’s files so that they are unreadable and useless. The only way they can get them back is if they pay an amount of money to the hacker usually through a secure and untraceable payment gateway such as bitcoin. A famous example of ransomware is the Wanacry virus unleashed to the public in 2017 and infected large businesses such as the NHS. 

 

Spyware 

Spyware is usually the most hidden type of malware as its whole objective is to not be detected. Spyware is secretly installed on a victim’s PC without their knowledge to spy on them to gather information. It can contain software like keyloggers and web redirectors to gather as much information as possible about the victim. Sometimes spyware can even change computer settings which can lead to slow internet connection speeds or changes in the web browser. 

Virus 

The term “virus” refers to how certain types of malware spread. Much like a real-life virus, it replicates itself all over the system including network file shares to increase the chance of it spreading across the computer network. 

Worm 

A worm is a standalone program that spreads across a network by itself. It is much like a virus however it does not need software attached to it to spread. Worms often cause harm to the network such as consuming bandwidth.