TL;DR -
ImunifyAV - A free version of malware scanner that detects any type of malicious file, including backdoors, web-shells, viruses, hacker tools, ‘blackhat SEO’ scripts, phishing pages, and many others. It just scans and notifies you without any cleaning capabilities. You will have to clean the infection manually on your own or restore the infected files from your backup.
ImunifyAV+ - An upgraded version of ImunifyAV+ with all the functions in ImunifyAV included. It detects and cleanup with advanced file deobfuscation techniques to enable detection of encrypted malicious code embedded in files with reputation management, which can be cleaned in one click manually.
Imunify360 - A complete security protection for Linux-based web servers and all hosted websites against malware infections, web attacks, vulnerability exploitation, and all other threats. It blocks attacks through all of the technologies at a time: signature matching, real-time behavior analysis for blocking malware, and cloud heuristics powered by insights collected from servers all over the world.
While you can upgrade your installation of ImunifyAV to ImunifyAV+, you will not be able to upgrade/downgrade between ImunifyAV(+) to Imunify360 or vice versa. To do this, the only way is to remove either of the software from your server in order to be able to install the other one.
