Well, the RSS spam crisis seems to have passed. We called the web host and after a hold of a mere 45 minutes they ran a clean-up program and found the offending files which had been embedded in the theme folders. Not sure how the original hack occurred, but there are a lot of WordPress vulnerabilities that still exist.
Sorry about that.
Heidi MacDonald is the founder and editor in chief of The Beat. In the past, she worked for Disney, DC Comics, Fox and Publishers Weekly. She can be heard regularly on the More To Come Podcast. She likes coffee, cats and noble struggle.