Targeting about:blocked?

[dominichayesferen]

I've been trying to no avail to figure out if one can inject about:blocked, the phishing page, with JS.

Right now, the only solution I've found to work is to replace it entirely with override chrome://browser/content/blockedSite.xhtml ../test.html.

[dominichayesferen]

It's notable that you can get this specific URL via document.documentURI.

[MrOtherGuy]

about:blocked is loaded in remote process with low privileges so it's similar to web-content or about:newtab in that scripts can't be injected into it directly.

You can however use the experimental window actor support (set userChromeJS.experimental.enabled to true and restart Firefox) to add behavior to about:blocked. The example about window actors in readme works for about:blocked as well, just replace the script header "windowActorMatches" to include about:blocked.