I’m using Redirection on a site and it gets a large number of 404s logged.

Here’s some examples:

/buy-viagra-online-cheap-with-no-prescription.pdf
Mozilla/5.0 (compatible; DotBot/1.1; http://www.opensiteexplorer.org/dotbot, [email protected])

/wp-content/cache/min/1/wp-content/plugins/jetpack/css/jetpack-a8a172f9c473757d7b64d826d81c927c.css
Mozilla/5.0 (iPhone; CPU iPhone OS 12_4 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/12.1.2 Mobile/15E148 Safari/604.1

/wp-content/plugins/social-warfare/css/style.min.css?ver=3.1.1
Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; Googlebot/2.1; +http://www.google.com/bot.html) Safari/537.36

/buy-viagra-online-united-states.pdf
Mozilla/5.0 (compatible; DotBot/1.1; http://www.opensiteexplorer.org/dotbot, [email protected])

/wp-content/cache/min/1/wp-content/plugins/scriptless-social-sharing/includes/css/scriptlesssocialsh
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/603.3.8 (KHTML, like Gecko) Version/10.1.2 Safari/603.3.8

Some of these requests relate to plugins that are on the site, while others do not. There’s certainly not any PDFs for buying Viagra or the like!

I see also that many visits are from bots.

Can you shed any light on this? I’m curious to know why this is happening and if it’s anything to be concerned about. It’s also a bit annoying because it’s hard to spot legitimate 404 errors.