Summary
Acunetix 360 detected an Apple's App-Site Association (AASA) file.
Impact
The AASA file in the .well-known directory is a way for developers to force iOS users to open certain parts of a website in the corresponding app instead of the browser.
Depending on its content, an attacker may find additional URLs and hidden endpoints, which aren't meant to be exposed, such as links that should only be visited by authenticated or privileged users. Additionally, the content of the file may aid an attacker during an initial reconnaissance phase.
Remediation
Be aware that the routes in these files are publicly accessible and make sure that the file or the routes do not contain any sensitive data.