BotBlocker is a free wordpress plugin that stops spam bots in your wodpress site.
Automatically stops spam-bots from commenting
no CAPTCHAS, math questions, passwords or extra input required
Zero false positives
Can be configured to completely block spam-bots or flag comments as spam
Hooks into wp-comments-post.php to prevent spam-bots from directly submitting spam comments
No API keys required
Login to wordpress (wp-admin).
In your admin dashboard click plugins and select Add New.
Type BotBlocker in the search field and click Search Plugins button.
After the successfully Installation click the activate Plugin link to activate the plugin.
Download BotBlocker wordpress plugin. Download link.
Unzip and upload it to your WordPress wp-content/plugins directory.
Login to wp-admin. In your admin dashboard click plugins and activate the BotBlocker wordpress plugin