That's not an outdated stack - just a stable one.

An outdated stack is a not-up-to-date version of Wordpress I foolishly set up because it was the last one compatible with a certain plugin used by a client on their website that I was recreating from the Wayback Machine.

The domain was put on a black list of dangerous sites (rightfully so, considering that the bot that hacked into it replaced the site with spam).