People used to go outside their houses and shake hands or even hug. Any storage media they had in their pockets could infect each other in this type of close contact.

One computer peed in another computer’s butt without protection. Sorry for being explicit.

It was a weird time to like computers. Nobody had an antivirus, and if they didn’t it never got updated. You’d just take floppy disks around to your friend’s house and plug them in. Windows gave everything admin rights.

To be honest, I was using a computer for about five years before the internet happened and I never got a virus.

Simple. The Internet wasn't invented, it was discovered. 'Viruses' have been aware of its existence from the beginning of time even though we so-called 'humans' weren't. Source: You can trust me, dawg.

They didn't as they didn't exist yet.

Non-internet viruses spread through other kinds of networks or by physically installing them from portable media.

(Real answer: The first virus was made in 1971 and was spread much the same way now, over ARPANET, the "proto-internet". It was called Creeper. So technically, there were no viruses before the invention of the internet)

Before there was internet, you had to bring your computer to another house for a LAN party. Sometimes other people brought theirs too, so you could play games.

With all those modems talking and making noises in the same room, if one of them was coughing or had a virus, it would easily spread to all the others.

First thing you need to realise, the internet has been around in one form or another for decades.

The internet as we know it has been around for over 30 years.

However, before widespread adoption of the internet, viruses were spread either by BBS services or via disk.

As a young Acorn achimedes user in the late 80s and early 90s I would obtain floppy disks with games on from friends, they would have obtained them from other friends who either downloaded them via BBS or bought them from a dodgy market stall. You could also buy them from magazine advertisements (I once bought a few floppy disks with porn on them).

There was always a risk that one of these disks had a virus on. For me it wasnt an issue. The Acorn used ROM to store the operating system and all your other files were kept on disks. We couldn't afford a hard drive so we were immune, however I did once have a disk that had a virus called Marburg on it according to our virus killer at the time.

You would get a floppy disk that had a virus buried in it in addition to the game/software. Often via trade of copied software, I think there were one or two instances of officially released floppies having been compromised in the factory, too, so every floppy sold of that particular software came with the virus.

It'd infect your computer, then embed itself on every floppy you'd make, some of which you'd inevitably trade with friends or whatever, thus infecting all their systems, so all floppies they'd write were infected, and they'd eventually trade with others, and so on and so on and so on.

Remove one instance of "internet" from the question and you'll get serious answers.

Snail mail

I don't know but they sure are itchy

I’m not computer historian but I’m thinking storage media like 5 inch floppies or 3.5 inch floppies or magnetic tape

Take a look at the SCA-Virus.

And regarding viruses spreading before the internet: there were BBS where you could upload and download files and if one of those files were infected and someone else downloaded it... Well you get the idea.

Floppy disks

Internet viruses came with the internet. But during the early years:

Pop ups.

Yeah it was mostly pop ups and occasionally links in emails.

Pop ups with porn were especially used for this because men are dumb and will click on titties.

People used to share the viruses because the virus would lock their computer and say something like "you must email this to 10 people to get back access". Or something like that. I forget exactly but that used to be a thing.

Your own family and friends would send you viruses.

Sony had a root kit on their music CDs. 💿

How did internet viruses spread before the internet was invented?

How many people died of car accidents before the car was invented?