It would be a tremendous help, if you provided us the name of the app.
Now we can only guess, but my educated guess is, that it’s a pre-SailJail app. This means, that the developer hasn’t chosen any specific set of permissions for the app and that is why the default sandboxing profile is being used. This basically enables all permissions so that older apps can remain functional.
If you wish, you can set your own permissions for the app, but this may cause disfunctionality. Further reading on the topic:
tl;dr: Any malicious activity is highly unlikely, but if you want to be certain, you can read the source code, provide us the name of the app and set app permissions according to your liking.