Thanks to Armin, I’ve discovered that spam links seem to be appearing in hidden links on this blog (they’re visible in the RSS feed).
I’ve found two on this page and zapped them both. The only culprit I can think of is an SEO plugin I installed today, so I’ve deactivated it. Can you let me know if the spam links recur, folks? Thanks.
Update: It doesn’t appear to be the SEO plugin; rather, a bug in the registration system that enables spammers to register and then edit other people’s posts. I’ve deleted a few suss-looking registrations so apologies if I’ve accidentally zapped a perfectly legitimate login.