Uninstall URCap in ursim

I’ve been playing around with URCaps using both Maven directly and through Eclipse. Now I want to clean up. I removed all .jar files from ursim/ursim-5.11.0.108249/.urcaps. But when I restart ursim, I still see some URCaps. I tried restarting the VirtualBox. But those URCaps are still there. Where do they come from? How can I uninstall them?