Valve added a "heartbeat" check. If Steam’s main thread fails to report a valid checksum of its own steamclient.dll every 10 seconds, it triggers a hard crash. Stealth Mode responded by intercepting the heartbeat and returning cached valid checksums.
Is GreenLuma Stealth Mode illegal? The answer varies by jurisdiction. greenluma stealth mode
According to documentation for versions like , Stealth Mode supports several key functions: Guide to Greenluma Stealth Mode Summary July 2021