Zero days also aren't malware necessarily. Zero days are usually bought and sold by those that use them to create malware they don't sell (to keep the 0day secr

Zero days also aren't malware necessarily. Zero days are usually bought and sold by those that use them to create malware they don't sell (to keep the 0day secret). Paid malware isn't all necessarily low quality, but most of it out there is. If you want something high quality I'd imagine you wouldn't see the listing for a particular malware that is high quality, but for someone who can write something high quality. Something custom developed will always be less detected than something being traded around.