Hey Timothy,
the Kanso theme uses the Grunion Contact Form as the basis for its contact form generator; there is no captcha available at the moment, can be emulated easily by including a “checkbox”-type field, declaring it as required and giving it a name like “Check this if you are human” :) However, if you do want a contact form with a captcha, I would recommend the Contact Form 7 plugin.
To reduce comment spam, you can also try Akismet, a tool built by the same team who created WordPress itself. Although it’s not 100% perfect, it should filter out the majority of spam messages for you (I’m using it on all my WP installs).
Sincerely,
Andrii / Satori Studio