Yeah, there are a few tools that can help you figure that out.
You could start by checking the Wayback Machine to see if the site's content or structure changed over time. It’s a simple way to catch anything that looks off.
If you have access to Google Search Console, that’s even better — it’ll show you if there are any manual penalties, indexing issues, or sudden drops in impressions/clicks.
Also, tools like Ahrefs or Semrush can show whether backlinks disappeared or if rankings dropped sharply for important keywords. That kind of stuff might point to sabotage or just poor maintenance.
If you suspect something was changed in the code, and you still have older backups or versions, you can use something like Diffchecker to compare files and spot any weird changes (like noindex tags or hidden redirects).
And yeah, if it’s a rented site and the original owner still had backend access, I’d definitely be suspicious too. Happens more often than people think.
