I can’t believe I didn’t know about Theme Authenticity Checker (TAC) from builtBackwards!
TAC is a plugin that examines themes for malicious code and static links. It’s a must-have.
None of the themes I’ve used on this site seem affected by anything bad, but it’s useful even if you download themes that don’t have anything dodgy about them. Sometimes it’s a pain in the patootie tracking down static links in themes, and this plugin points you straight at them and lets you open up the files in the editor.
Many thanks to Siobhan Ambrose of WPMU.org for her excellent article, Why You Should Never Search For Free WordPress Themes in Google or Anywhere Else.
I hope Siobhan is getting paid or laid for all her hard work. She certainly puts a lot of effort into her articles – unlike yours truly, who just rants about whatever comes to mind in the course of work and play.