Dotfuscator can inject code into applications to check if tampering has occurred. For example, if an attacker attempts to circumvent your application's licensing requirements or modify your binary, you would not know about it unless your application had been instrumented with tamper detection and notification. In essence, Tamper Check detects unauthorized tampering of your application's source code. Once the tamper is detected, you can receive notification, shut down the application, or take other customized actions.
Learn more in the Dotfuscator User Guide: