Browse Rules

M365 Identity User Account Lockouts

Detects a burst of Microsoft 365 user account lockouts within a short 5-minute window. A high number of IdsLocked login errors across multiple user accounts may indicate brute-force attempts for the same users resulting in lockouts.

M365 Exchange Inbox Forwarding Rule Created

Identifies when a new Inbox forwarding rule is created in Microsoft 365. Inbox rules process messages in the Inbox based on conditions and take actions. In this case, the rules will forward the emails to a defined address. Attackers can abuse Inbox Rules to intercept and exfiltrate email data without making organization-wide configuration changes or having the corresponding privileges.

M365 Exchange Mailbox High-Risk Permission Delegated

Identifies the assignment of rights to access content from another mailbox. An adversary may use the compromised account to send messages to other accounts in the network of the target organization while creating inbox rules, so messages can evade spam/phishing detection mechanisms.

M365 Identity User Brute Force Attempted

Identifies brute-force authentication activity targeting Microsoft 365 user accounts using failed sign-in patterns that match password spraying, credential stuffing, or password guessing behavior. Adversaries may attempt brute-force authentication with credentials obtained from previous breaches, leaks, marketplaces or guessable passwords.

M365 OneDrive/SharePoint Excessive File Downloads

Identifies when an excessive number of files are downloaded from OneDrive or SharePoint by an authorized user or application in a short period of time. This may indicate a potential data exfiltration event, especially if the downloads are performed using OAuth authentication which could suggest an OAuth phishing attack such as Device Code Authentication phishing.

M365 Exchange Inbox Rule with Obfuscated Name

Identifies when a Microsoft Exchange inbox rule is created or modified with a name composed only of special characters. Adversaries may use obfuscated inbox rule names to evade detection, hide malicious forwarding or deletion rules, or blend in with benign audit noise. The rule name is parsed from "o365.audit.ObjectId", which encodes the mailbox identity and rule name separated by a backslash.

Deprecated - M365 Security Compliance Potential Ransomware Activity

Identifies when Microsoft Cloud App Security flags potential ransomware activity in Microsoft 365. This rule detects events where the Security Compliance Center reports a "Ransomware activity" or "Potential ransomware activity" alert, which may indicate file encryption, mass file modifications, or uploads of ransomware-infected files to cloud services such as SharePoint or OneDrive.

Multiple Device Token Hashes for Single Okta Session

This rule detects when a specific Okta actor has multiple device token hashes and multiple source IPs for a single Okta session. This may indicate an authenticated session has been hijacked or replayed from a different device and network. Adversaries may steal session cookies or tokens to gain unauthorized access to Okta admin console, applications, tenants, or other resources.

M365 Teams Rogue Help Desk Chat Created

Identifies a one-on-one Microsoft Teams chat created by a user from a foreign tenant whose display name, member profile, or email local-part resembles IT help desk or Microsoft security staff. Adversaries abuse cross-tenant Teams external access to impersonate support personnel and socially engineer victims into granting remote access or disclosing credentials.

M365 Identity Global Administrator Role Assigned

Identifies when the Microsoft 365 Global Administrator or Company Administrator role is assigned to a user or service principal. The Global Administrator role has extensive privileges across Entra ID and Microsoft 365 services, making it a high-value target for adversaries seeking persistent access. Successful assignments of this role may indicate potential privilege escalation or unauthorized access attempts, especially if performed by accounts that do not typically manage high-privilege roles.

M365 SharePoint Site Administrator Added

Identifies when a new SharePoint Site Administrator is added in Microsoft 365. Site Administrators have full control over SharePoint Sites, including the ability to manage permissions, access all content, and modify site settings. Adversaries who compromise a privileged account may add themselves or a controlled account as a Site Administrator to maintain persistent, high-privilege access to sensitive SharePoint data. This technique was notably observed in the 0mega ransomware campaign, where at

M365 Exchange Inbox Phishing Evasion Rule Created

Identifies when a user creates a new inbox rule in Microsoft 365 that deletes or moves emails containing suspicious keywords. Adversaries who have compromised accounts often create inbox rules to hide alerts, security notifications, or other sensitive messages by automatically deleting them or moving them to obscure folders. Common destinations include Deleted Items, Junk Email, RSS Feeds, and RSS Subscriptions. This is a New Terms rule that triggers only when the user principal name and associa

M365 Potential AiTM UserLoggedIn via Office App (Tycoon2FA)

Detects Microsoft 365 audit "UserLoggedIn" events consistent with Tycoon 2FA phishing-as-a-service (PhaaS) adversary-in-the-middle (AiTM) activity: the Microsoft Authentication Broker requesting access where the object identifier matches Microsoft Graph or Exchange Online, or the Office web client application authenticating to itself, combined with Node.js-style user agents (node, axios, undici). Tycoon 2FA bypasses MFA by relaying authentication and capturing session material, often targeting M

Entra ID Concurrent Sign-in with Suspicious Properties

Identifies concurrent azure signin events for the same user and from multiple sources, and where one of the authentication event has some suspicious properties often associated to DeviceCode and OAuth phishing. Adversaries may steal Refresh Tokens (RTs) via phishing to bypass multi-factor authentication (MFA) and gain unauthorized access to Azure resources.

M365 Exchange MFA Notification Email Deleted or Moved

Identifies when an MFA enrollment, registration, or security notification email is deleted or moved to deleted items in Microsoft 365 Exchange. Adversaries who compromise accounts and register their own MFA device often delete the notification emails to cover their tracks and prevent the legitimate user from noticing the unauthorized change. This technique is commonly observed in business email compromise (BEC) and account takeover attacks.

M365 Quarantine and Hygiene Signal

Identifies Microsoft 365 email quarantine, hygiene, and mail submission events. These signals indicate blocked threats, spam filtering actions, and user-reported suspicious emails. While these represent blocked or mitigated threats, they provide valuable telemetry for understanding attempted attacks and attack patterns. This building block rule generates security events for correlation, threat hunting, and telemetry collection.

M365 AIR Investigation Signal

Identifies Microsoft 365 Automated Investigation and Response (AIR) events including automated investigations, manual investigations, and admin-initiated actions. These events track Microsoft's automated threat response activities and can indicate active threats being remediated. This building block rule generates security events for correlation, threat hunting, and telemetry collection to provide visibility into automated response actions.

M365 or Entra ID Identity Sign-in from a Suspicious Source

This rule correlate Entra-ID or Microsoft 365 mail successful sign-in events with network security alerts by source address. Adversaries may trigger some network security alerts such as reputation or other anomalies before accessing cloud resources.

M365 Identity Device Code Grant with Unusual User and ASN

Identifies a Microsoft 365 OAuth device code grant ("Cmsi:Cmsi") with application Microsoft Authentication Broker ("29d9ed98-a469-4536-ade2-f981bc1d605e") for Microsoft Graph from a source ASN not previously observed for that user in a historical window. Phishing kits leveraging device code phishing complete the full login (password and MFA) at the genuine Microsoft endpoint and harvest the resulting token by polling, so MFA does not stop them and the authorization commonly originates from attac

Entra ID Sign-in Brute Force Attempted (Microsoft 365)

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 Te

M365 SharePoint Search for Sensitive Content

Identifies search queries in SharePoint containing sensitive terms related to credentials, financial data, PII, legal matters, or infrastructure information. Adversaries who compromise user accounts often search for high-value files before exfiltration. This rule detects searches containing terms across multiple sensitivity categories, regardless of the access method (browser, PowerShell, or API). The actual search query text is analyzed against a curated list of sensitive terms to identify pote

M365 SharePoint Site Sharing Policy Weakened

Identifies when a SharePoint or OneDrive site sharing policy is changed to weaken security controls. The SharingPolicyChanged event fires for many routine policy modifications, but this rule targets specific high-risk transitions where sharing restrictions are relaxed. This includes enabling guest sharing, enabling anonymous link sharing, making a site public, or enabling guest user access. Adversaries who compromise administrative accounts may weaken sharing policies to exfiltrate data to exter

M365 Security Compliance Admin Signal

Identifies administrative actions in the Microsoft 365 Security & Compliance Center including cmdlet execution, RBAC changes, security insights, and user permission modifications. These events can indicate legitimate administrative activity or potential defense evasion through security control modifications such as DLP policy removal, compliance rule changes, or privilege escalation. This building block rule generates security events for correlation, threat hunting, and telemetry collection.

M365 Defender Alerts Signal (UAL)

Identifies alerts generated by Microsoft Defender products including Windows Defender for Endpoint (WDATP), Microsoft Cloud App Security (MCAS), Microsoft Defender for Identity, Microsoft 365 Defender custom detections, and Defender Experts for XDR via M365 Unified Audit Logs (UAL). These cross-platform alerts indicate detected threats across endpoints, cloud applications, and identity systems. This building block rule generates security events for correlation, threat hunting, and telemetry coll

Deprecated - Azure Entra Sign-in Brute Force Microsoft 365 Accounts by Repeat Source

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.