Developers of such mods reverse-engineer the original WhatsApp APK, add features, re-sign the app with a different cryptographic key, and redistribute it.
Before downloading and installing WhatsApp X 7.2 APK, keep in mind:
: Because these apps are not verified, there is no guarantee your messages remain end-to-end encrypted. Attackers can intercept your metadata or even hijack your account entirely.
APK files from unverified sources often contain spyware or trojans designed to steal banking info or passwords.