Hi Ananyme,
Since it was an accidental download from the App Store, then you do not have to be concerned. However, if you think your Apple ID account has been compromised, then you can complete the steps listed here: If you think your Apple ID has been compromised - Apple Support that are also listed below.
Gain control of your Apple ID
If you think your Apple ID is compromised, use these steps to gain control of it and review your account information:
- Sign in to your Apple ID account page. If you can't sign in or you receive a message that the account is locked when you try to sign in, try to reset or unlock your account.
- Change your Apple ID password and choose a strong password.
- Review all the personal and security information in your account. Update any information that isn't correct or that you don’t recognize, including:
- Your name.
- Your primary Apple ID email address.* If you need to change your email address, update the features and services that you use with Apple ID, so that each one is using your updated Apple ID.
- All alternate email addresses, rescue email addresses, and phone numbers.
- The devices that are associated with your Apple ID, if you've already set up two-factor authentication.
- Security questions and answers. If you think they might be easy to guess, you should change your security questions.
4. Check with your email address* provider to make sure that you control every email address associated with your Apple ID. If you don't control the email addresses associated with the Apple ID, you should change the password for the email address or use a different email address.
5. Set up two-factor authentication for your Apple ID. This additional security feature is designed to prevent anyone from accessing your account, even if they know your password.
Best regards