How can I stop redirects to adult sites?

First, does it happen on one website or across lots of unrelated sites? If it is just one, the site or its ads may be causing the redirects. Avoid it and try a reputable content blocker such as uBlock Origin if your browser supports it.

If it happens everywhere, check your installed browser extensions and remove anything unfamiliar. A browser reset is another option, though it may change settings you wanted to keep.

Check your browser's site permissions, especially notifications and pop-ups. Remove permissions for sites you don't recognize. Clearing browsing data may help too, although it can sign you out of websites.

You can try filtered DNS as an extra layer. Cloudflare's adult content and malware filter uses 1.1.1.3 and 1.0.0.3 for IPv4. Set it on the device or router, depending on what you want covered.

It won't fix the source of a redirect and it won't block everything, so treat it as a filter rather than a repair.

If redirects continue across unrelated sites after checking the browser, run a reputable malware scan. AdwCleaner or the free version of Malwarebytes are options for a computer. Redirects alone don't prove there's a trojan, though.