After activating a plugin I received an email that I had never recived before. What kind of miscellaneous code it might be? it's a coincidence? I received an email to my account Gmail that I never used on my VPS (not sure) and I am sure that I never used it on the website where I activated a plugin. But I activated the plugin exactly at 1:03 and I received SPAM (with pdf and link inside pdf) exactly at 1:03. I blocked using the root user years ago. I am using admin user of VestaCP.
My question is how can I scan WordPress plugin for malware or miscellaneous code or malware? I tried uploading zip with the plugin on virustotal but nothing was found.
I need some help before I reinstall my VPS and all my websites.
Thank you