How does an app “detect” hooking?

There are a few approaches:

• The app can check its own integrity and environment at runtime. If something doesn’t look as expected (for example, a critical function’s code has been altered in memory, or an unexpected library is loaded into the app’s process), the app might suspect a hook.

• It can also look for known footprints of hooking frameworks. Many hooking tools leave telltale signs (specific file names, process names, or injected code patterns) that can be recognized. For instance, if a well-known hooking tool is attached, the app might notice unusual debug connections or the presence of classes and methods that only exist when a framework like Xposed or Frida is in use.

• Hook detection often goes hand-in-hand with root detection or jailbreak detection. Since hooking typically requires elevated privileges, an app that finds a device is rooted/jailbroken will treat it as a higher-risk environment and may assume a hooking attack is possible. Some apps refuse to run in such cases or operate in a limited mode.

In essence, hook detection is any check or safeguard that allows an app to sense “I’m being watched or controlled by someone else’s code right now.” Once detected, the app can then respond (for example, by shutting down, disabling sensitive features, or alerting the user).