Marvel's Avengers was never released as a free-to-play game. Any site claiming to offer it for free is likely hosting a pirated or "cracked" version, which is illegal and unsafe for your hardware.
Files from unofficial sources often contain malware, ransomware, or spyware. marvels-avengers-free-download-pc-game-full-version
On September 30, 2023, Crystal Dynamics ended official support for the game and , including Steam, Xbox, and PlayStation. Marvel's Avengers was never released as a free-to-play game