How can defenders protect against this type of Warcraft III map attack?

Defenders should avoid playing custom maps from untrusted sources, enable antivirus with real-time scanning of startup folders, and consider restricting write permissions to the startup directory. Additionally, monitoring for unusual `war3map.j` scripts that contain Preload function calls targeting `.bat` extensions can help detect malicious maps. For more advanced defense concepts, refer to the Introduction to Process Doppelganging Exploitation.