Eli5 – How are computer viruses created without destroying the creator’s computer first?

Question

I’ve always wondered how computer viruses are made. If someone creates a virus on their own computer, wouldn’t it infect and potentially destroy their system first before it’s spread to others?

In: 249

Answer 1

1. Permissions. If the virus may not do damage, it can’t – unless it exploits a vulnerability.
2. Triggers. If there is something that prevents the damage to happen, it doesn’t happen. E.g. the Morris worm (RFC1135) would have needed a trigger
3. Using a separate device for development (VM or hardware). Virus or kernel driver: Don’t do that on the same machine you need tomorrow to file taxes. Also don’t be connected to the internet.
4. Having a way to undo the damage.