Would a hard drive wipe be enough to remove any potential viruses?

[jr738gjr]

So basically a couple of weeks ago I was trying to find an illegal pdf of a book(WH40K rulebook) online but I wasn't finding it easily. I ended up on this dodgy af website where it basically blank white, with an image of a soldier on it and a link. That was it. I knew the website looks massively suspicious and it was stupid of me to click on the link but I did anyway because I was desperate. I think I saw something download but nothing happened after that and I didn't see any extra file somewhere. I never noticed anything else suspicious on my MacBook after that.

Yesterday I became so paranoid that someone was watching everything I was doing or something like that, that I decided to erase the hard drive. My MacBook is new so I didn't have anything important to save so I just erased it without backing anything up. I noticed after I reinstalled macOS that FileVault or something was on and it saved some files, would that matter?

TL;DR I'm paranoid about a virus, decided to erase the hard drive, would that potentially have any effect is there was a virus?

 

[jerryk]

If you wipe the drive you should be clear.

 

[ZapNZs]

While there have been lab demonstrations of malware that targets firmware (and consequently even throwing away the hard drive fails to remove the malware,) Macs tend to be very robust against most malware. Just because a website tries to force a download of a harmful program, what that program can do is still usually going to be isolated unless you do one of more of the following: 1) open it, 2) disable certain security settings to allow installs from untrusted sources, 3) provide the program with elevated privileges by entering your password, and 4) disable System Integrity Protection.

In other words, even if the account you were using was an Admin account, and the download contained a virus (versus some unwanted adware or crapware), and that virus happened to target Macs (most will target Windows), and that virus happened to defeat the malware protection that browsers have built-in, what that virus can do to your computer is usually very limited. So it is unlikely that it was necessary to reinstall the OS, and, if there was an issue, the reinstall almost certainly cleared it.

FileVault being on is a good thing and should be on by default. This is Apple's full-disk encryption, and full-disk encryption keeps your files safe (unlike a simple password protection without encryption.) What do you mean by "saved some files"?