From what I’ve seen, negative SEO isn’t as effective as it used to be, especially for established sites. Google seems much better now at ignoring low-quality or spammy backlinks.
That said, I don’t think it’s completely gone. Smaller or newer sites with weaker link profiles can still feel some impact if there’s a sudden spike of low-quality links or other suspicious signals.
In terms of protection, I think regularly monitoring your backlink profile, keeping your site technically clean, and building a strong, natural link base over time helps a lot. A solid foundation makes it much harder for any external activity to cause damage.
It’s not something I’d worry about too much day-to-day, but definitely worth keeping an eye on.