Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
The error message AADSTS900561: The endpoint only accepts POST requests. Received a GET request. indicates a sign-in attempt was made incorrectly (using HTTP GET instead of POST) against a Microsoft Entra ID endpoint. This by itself does not prove compromise; it is often just a failed or malformed sign-in attempt.
To address the concern about possible account compromise and unusual sign-ins from other countries, follow these steps:
- Review recent sign-in activity
- Go to the My Account portal and open My sign-ins:
- Sign in with the work or school account.
- Select Recent Activity from the left navigation.
- Expand each sign-in entry and verify:
- Location (country/region and city)
- Browser and operating system
- App or resource accessed
- If any successful sign-in is not recognized (for example, from Peru or Iraq), treat the account as compromised.
- Go to the My Account portal and open My sign-ins:
- If suspicious or unauthorized sign-ins are found
- Immediately change the account password.
- Go to Security info (from the same portal) and:
- Review and update authentication methods.
- Remove any methods that are not recognized.
- Sign out of all sessions if that option is available in the security settings.
- Use Microsoft’s hacked/compromised account guidance
- Follow the official guidance for compromised Microsoft accounts to:
- Secure the account.
- Review and remediate any malicious changes.
- Follow the official guidance for compromised Microsoft accounts to:
- Monitor for future unusual sign-ins
- Microsoft sends alerts (email/SMS) when unusual sign-ins occur (for example, from new locations or devices).
- When such an alert is received, promptly review the Recent activity page and confirm whether it was legitimate.
If the account is a personal Microsoft account (not work/school) and appears hacked, use the hacked-account recovery flow and, if needed, the Sign-in Helper tool to regain control.
References:
- View your work or school account sign-in activity from My Sign-ins
- What happens if there's an unusual sign-in to your account
- How to recover a hacked or compromised Microsoft account
- Hello , welcome to Account help & learning
- Microsoft account has been locked
- Unblock my Outlook.com account
- Respond to a compromised cloud email account
- My account got hacked. - Microsoft Q&A
- My account got hacked - Microsoft Q&A
- How do I send an email to Microsoft about my account being hacked and taken over by <removed> ? - Microsoft Q&A
- my microsoft account has been compromised - Microsoft Q&A
- Hacker set up continuous draft ransomware email - Microsoft Q&A