Identifies potential brute-force attacks targeting Microsoft 365 user accounts by analyzing failed sign-in patterns in Microsoft Entra ID Sign-In Logs. This detection focuses on a high volume of failed interactive or non-interactive authentication attempts within a short time window, often indicative of password spraying, credential stuffing, or password guessing. Adversaries may use these techniques to gain unauthorized access to Microsoft 365 services such as Exchange Online, SharePoint, or Teams.

Read More

Identifies a high count of failed Microsoft Entra ID sign-in attempts as the result of the target user account being locked out. Adversaries may attempt to brute-force user accounts by repeatedly trying to authenticate with incorrect credentials, leading to account lockouts by Entra ID Smart Lockout policies.

Read More

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 with a high number of distinct session IDs. Adversaries may programmatically attemopt to brute-force TOTP codes by generating several sessions and attempt to guess the correct code.

Read More

Identifies potential brute-force attacks targeting user accounts by analyzing failed sign-in patterns in Microsoft Entra ID Sign-In Logs. This detection focuses on a high volume of failed interactive or non-interactive authentication attempts within a short time window, often indicative of password spraying, credential stuffing, or password guessing. Adversaries may use these techniques to gain unauthorized access to applications integrated with Entra ID or to compromise valid user accounts.

Read More

Identifies separate OAuth authorization flows in Microsoft Entra ID where the same user principal and session ID are observed across multiple IP addresses within a 5-minute window. These flows involve the Microsoft Authentication Broker (MAB) as the client application and the Device Registration Service (DRS) as the target resource. This pattern is highly indicative of OAuth phishing activity, where an adversary crafts a legitimate Microsoft login URL to trick a user into completing authentication and sharing the resulting authorization code, which is then exchanged for an access and refresh token by the attacker.

Read More

This rule correlate Azure or Office 356 mail successful sign-in events with network security alerts by source.ip. Adversaries may trigger some network security alerts such as reputation or other anomalies before accessing cloud resources.

Read More