HOSTFLOW MALWARE REMOVER
Backdoor mainly happens when you are using a crack plugin even if you remove the crack plugin it won't fix it as it INFECTS all other plugins and server main jar also.
I am here to tell you a solution for fixing this issue.
If your server is also Backdoored then please follow these steps to get rid of the backdoor.
1. Stop your server
2. Open File manager and Delete all the .jar files /Plugin Jar present in plugins folder also delete the main server.jar (OR whichever .jar file you have in main files from where you choose plugins folder to open it)
3. Re-download all Plugins and Server Jar from Original Sources in a Folder on your pc, so you can upload them together. (SpigotMC, Mc-Market, Polymart are Trusted)
4. Ensure you don't use any Cracked Paid Plugins or infected plugins in this new folder of fresh plugins.
5. Ensure you don't leave any .jar file in your File Manager and plugins folder before uploadin New Fresh jars.
6. Now add/Upload that fresh new Jars to the server (If the .jar file is a plugin then ensure you upload it in the plugins folder & Upload the Server Jar in Base File manager) and start it again.
Q. How to see if a plugin is Cracked?
A. If you are adding a paid plugin and you have not purchased it and downloaded it for free from any illegal Site (Like BlackSpigot, GhostLeaks, Direct Leaks, etc) then it is a Cracked plugin with Virus in it.
Q. I did it still the Hacker is able to Spam Messages and Do things
A. This means any of your Paid plugins is still cracked or obtained Illegally.
The person who is doing this is doing it because he wants people not to use Cracked Plugins, This guy is good as he is just Informing People, but a Bad Hacker will do anything much Worst.