Computer Viruses Explained

Everyone who has used a computer has heard of a computer virus at one time or another. It’s the most popular term used when talking about online security but is often a misunderstood term. A computer virus is just one malware type. Malware is any software that harms a computer system against the owner’s wishes. When someone says that they have a computer virus, this is not accurate; they have malware on their machine. Here, I go into the different types of malware that can infect a machine and why it’s dangerous to have malware remain on a computer.

What is a computer virus?

A computer virus is a malware type that spreads by infecting other computer programs by inserting its code into another computer program to spread. Typically, viruses attach themselves to an executable file, and every time someone runs that program, the code will execute and attach itself to another program. When someone shares an infected program with another computer, either by disk or over a computer network, the virus can move from one computer to another, continuing this process. Since viruses rely on other programs to spread, computer viruses aren’t the most dangerous types of malware in cybersecurity.

A computer worm is another malware type that can spread without infecting any other type of program. A worm will duplicate itself and spread to any machine on the computer network with the vulnerability it exploits. Computer worms can spread much faster than a virus and are generally more difficult to contain.

A trojan horse is another malware type that deceives people into downloading and running it by pretending to be a legitimate program. For example, someone can attach a file that looks like an excel file and has a legitimate-sounding name - to an email. This may convince the recipients to download that file and permit it to run. This is an example of a trojan horse.

The last malware type I will discuss is scareware, a type of malware that tries to scare people into downloading it. For example, when visiting a website, a pop-up saying that your machine has been hacked and instructed that it will remove the malware for you if you download this antivirus solution. This is an example of someone using scareware to try and scare people into downloading malware. These are just a few malware examples often confused with being a computer virus, but each of these is a different type of malware with a different means of spreading to other computers.

What can computer viruses do to a machine?

Logically, why do people even bother with creating computer viruses? The primary motivation for creating these computer programs is monetary gain. Cybercrime has become an extremely profitable business that has led to many more strains of computer viruses. Here are some of the ways virus and malware creators make money:

Ransomware: Ransomware is used to encrypt the files on computer systems so that the owner can’t access them, and the hacker demands a ransom payment to decrypt the information. Since many businesses need their data to operate, most companies will pay the ransom to get their information back.

Selling personal information: Information like credit cards, social security numbers, email addresses all value the black market. Hackers will take this information from their victims and sell it online for a profit.

Adware: Some malware is configured to show pop-up ads that will generate profit for the malware owner. This type of malware doesn’t cause damage, but it is still an annoyance.

Crypto mining: Some malware is designed to hijack the computing resources and use them to mine cryptocurrency for the program’s owner. Cryptocurrencies like Bitcoin and Ethereum are extremely profitable right now, so this type of malware can generate a lot of money for the criminal hacker.