There are many plugins available to protect WordPress websites from malicious and security attacks. Among the best of these add-ons are:

1. Wordfence Security : Provides an intuitive user interface and enables features such as traffic monitoring, firewall, and malware scanning.
2. Sucuri Security : Provides advanced protection against malicious attacks including DDoS protection, secure scanning, and malware removal.
3. BulletProof Security : Provides custom protection settings, real-time monitoring of attacks, and protection of .htaccess files.
4. All In One WP Security & Firewall : Offers an intuitive user interface and enables features like account protection, firewall, and malware scanning.

Remember, it’s also important to update your plugins and themes regularly and implement other security practices like using strong passwords and backing up the site regularly.

The best WordPress plugins for spam

There are several anti-spam plugins available for WordPress. Among the best add-ons to protect your site from spam:

1. Akismet : It is considered one of the most popular anti-spam plugins for WordPress. It analyzes comments and prevents spam from accessing your site.
2. Antispam Bee : Another plugin that is effective in blocking spam comments and unwanted emails.
3. Spam Protection, AntiSpam, FireWall by CleanTalk : Provides powerful anti-spam functionality including protection against automated comments, contact forms, and emails.
4. Wordfence Security : Although it is considered a comprehensive security tool, it also provides anti-spam functions such as blocking bad IP addresses and monitoring spam.

Remember, you may need to experiment with a few plugins to see which ones work best for your site and meet your security needs.

Here is also a list of some of the best cache plugins for WordPress:

1. WP Rocket : A premium plugin that provides a simple and powerful interface to improve your site’s performance by enabling cache storage, file compression, improving delayed loading, and much more.
2. W3 Total Cache : Provides comprehensive functionality for caching and improving site performance, including reducing loading time and improving user experience.
3. WP Super Cache : A simple and powerful plugin that generates static HTML pages to reduce loading time and avoid server overload.
4. LiteSpeed ​​Cache : Provides excellent performance with advanced cache algorithms and direct support for servers using LiteSpeed ​​technology.
5. Cache Enabler : A lightweight and simple add-on to activate cache storage and improve site performance.
6. Comet Cache : Offers powerful cache functionality with extensive customization and support for shared hosts and dedicated servers.

Remember to choose the plugin that best meets your site’s needs and is compatible with your hosting environment and site performance requirements. Always run performance tests before and after installing a plugin to ensure your site’s performance is optimized.