Identifies potential brute-force (password spraying) attempts against Azure Entra ID user accounts by detecting a high number of failed non-interactive single-factor authentication (SFA) login attempts within a 10-minute window. Attackers may attempt to brute force user accounts to gain unauthorized access to Azure Entra ID services. Non-interactive SFA login attempts bypass conditional-access policies (CAP) and multi-factor authentication (MFA) requirements, making them a high-risk vector for unauthorized access. Adversaries may attempt this to identify which accounts are still valid from acquired credentials via phishing, infostealers, or other means.

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Identifies rare Azure Entra ID apps IDs requesting authentication on-behalf-of a principal user. An adversary with stolen credentials may specify an Azure-managed app ID to authenticate on-behalf-of a user. This is a rare event and may indicate an attempt to bypass conditional access policies (CAP) and multi-factor authentication (MFA) requirements. The app ID specified may not be commonly used by the user based on their historical sign-in activity.

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Identifies rare instances of authentication requirements for Azure Entra ID principal users. An adversary with stolen credentials may attempt to authenticate with unusual authentication requirements, which is a rare event and may indicate an attempt to bypass conditional access policies (CAP) and multi-factor authentication (MFA) requirements. The authentication requirements specified may not be commonly used by the user based on their historical sign-in activity.

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Identifies brute force attempts against Azure Entra multi-factor authentication (MFA) Time-based One-Time Password (TOTP) verification codes. This rule detects high frequency failed TOTP code attempts for a single user in a short time-span. Adversaries with valid credentials, when attempting to login to Azure portal or other Azure services, may be prompted to provide a TOTP code as part of the MFA process. If successful, adversaries can bypass MFA and gain unauthorized access to Azure resources.

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Identifies potential brute-force attempts against Microsoft 365 user accounts by detecting a high number of failed interactive or non-interactive login attempts within a 30-minute window. Attackers may attempt to brute force user accounts to gain unauthorized access to Microsoft 365 services via different services such as Exchange, SharePoint, or Teams.

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Identifies potential brute-force attempts against Microsoft 365 user accounts by detecting a high number of failed interactive or non-interactive login attempts within a 30-minute window from a single source. Attackers may attempt to brute force user accounts to gain unauthorized access to Microsoft 365 services via different services such as Exchange, SharePoint, or Teams.

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