Awais

Simple Spam Blocker use honeypot technique which is fast and easy way to prevent spam. This plugin can stop spam comments, spam registration and also can be used to stop bots to try to login into admin panel. This plugin also provide option to stop spammers to get register via Ultimate Memeber Plugin’s registration from. You can also use shortcode [simple-spam-blocker] on any form to stop spammers.

Simple Spam Blocker

Simple Spam Blcoker stop spam comments and also can be used to stop bots to try to login into admin panel.

Richard Phillips

SpamScrubber helps block bots and spam submissions by: 
– Adding a customizable delay to all form submit buttons. 
– Obfuscating form actions for non-JavaScript users. 
– Adding a honeypot field (with customizable label) to trap bots. 
– Blocking direct POSTs by requiring a JavaScript token. 
– Providing admin stats for various spam attempt types.
<h3>License</h3>
This plugin is free software released under the GPLv2 or later.

SpamScrubber

A simple and robust anti-spam plugin that adds a submission delay, JavaScript token, and a honeypot field to your site's forms.

Simple Spam Blocker vs SpamScrubber