Depends on your browsing habits. If you're only visiting a handful of trustworthy websites maybe never. If you spend nine hours a day on bootleg hentai streaming sites, maybe very quickly.
Maybe. See we had a trusted B2B site we use for stock. Then we noticed our bank account being raided. Turns out they had hackers on their system skimming all the card details.
Maybe they were hosting on XP. Didn’t ask.