sushiinthecan asks: So, is there anything we can do to avoid this? Or at least know if what we are about to reblog is infected?

» SFB says: Yes — the key thing is to check your browser to make sure there’s nothing rogue on it (say, extensions you didn’t install) and to be sure everything is updated to the latest version, and as far as reblogging stuff, click on the “HTML” tag in the posting interface to view the source code. If there is something there that shouldn’t be — it’d look similar to the top image on our last post, particularly the top line — delete it. It appears to be a browser hijack rather than a theme hijack, as it adds the code to the bottom of posts, but users can spread the offending code on their own Tumblrs unwittingly. It looks like the code adds ad links to affected Tumblrs. — Ernie @ SFB