Malware Cleanup and Prevention for Wordpress Sites

I have 10 WordPress websites on a shared cPanel, some of which are infected with the same malware. The issue stems from a rogue plugin on one site. Although our server employs Monarx for protection, it doesn't address the root cause. I need a professional to both remove the malware and implement a prevention plan to avoid future incidents.

I will provide:
- A comprehensive Monarx log detailing malicious files created over the past week
- WordPress checksums indicating affected files after a fresh core installation
- A screen share video explaining the issue

Your Role:
- Utilize a combination of manual cleaning and automated tools to eradicate the malware
- Identify the root cause of the issue
- Develop and implement a prevention strategy

Skills Required:
- Extensive experience with WordPress and cPanel
- Proficient in malware removal and website security
- Knowledgeable in developing prevention strategies
- Familiar with Wordfence and Monarx

This project requires minimal downtime for research. I expect the job to be done efficiently and effectively. Please note, I already have Wordfence on the WordPress sites and Monarx on the server. I need at least a 4-6 week assurance that these issues won't come back.