I have an issue where a form on my site is getting spammed. The form is actually a copy paste job from a CRM, so I cannot access any of the server side script to make a good human checker.
In the interim I have made a very simple JQuery checker.
My question is, do spam bots load the DOM thus triggering the JavaScript checker?
It might already be too late to use this idea since the spammers already know about the form: leave out a critical piece of your form (like the action attribute) and populate it using javascript when the document is loaded. Do tell visitors that the form doesn't work if javascript is disabled and remove this message when the form is set up correctly.
Generally the answer is still no. There are apps nowadays like PhantomJS that make it easier for an automated program to run a browser including JavaScript, however, they are typically slower.
It's often much easier to scrape HTML and send direct POST requests. If a bot has problems on one site (e.g. a CAPTCHA) it will just move onto another.
So if you have no access to the server side code, you might be out of luck. If the form is being sent to your email perhaps a better spam filter on your email is a good defense.
