InvalidSign is a security research tool designed to bypass endpoint detection and response (EDR) solutions that block execution of known malicious signed applications. The tool works by obtaining valid signed files with different hash values, effectively circumventing signature-based detection mechanisms that rely on file hashes to identify and block malicious executables. InvalidSign demonstrates this bypass technique through analysis of legitimate system files like cmd.exe and generates test files to validate the evasion method. The tool focuses on exploiting the gap between signature validation and hash-based detection, allowing researchers to understand how signed malware can evade certain security controls. This research tool helps security professionals understand the limitations of hash-based detection systems and the potential for abuse of legitimate code signing certificates.