Many online references to "MCSpam.pw" date back to approximately 2019-2020, suggesting the tool is an older generation of Minecraft stress-tester.
These bots perform rapid reconnections and flood chat or server resources, which can bypass basic antibot plugins that do not account for IP-checking or cloud-optimized processing. MCSpam.pw.zip
RAntiBot Simple and Effective AntiBot plugin BUIL-5 - SpigotMC Many online references to "MCSpam