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.

Read More

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.

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

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.

Read More

Identifies attempts to register a new device in Microsoft Entra ID after OAuth authentication with authorization code grant. Adversaries may use OAuth phishing techniques to obtain an OAuth authorization code, which can then be exchanged for access and refresh tokens. This rule detects a sequence of events where a user principal authenticates via OAuth, followed by a device registration event, indicating potential misuse of the OAuth flow to establish persistence or access resources.

Read More

Detects potentially suspicious OAuth authorization activity in Microsoft 365 where the Visual Studio Code first-party application (client_id = aebc6443-996d-45c2-90f0-388ff96faa56) is used to request access to Microsoft Graph resources. While this client ID is legitimately used by Visual Studio Code, threat actors have been observed abusing it in phishing campaigns to make OAuth requests appear trustworthy. These attacks rely on redirect URIs such as VSCode Insiders redirect location, prompting victims to return an OAuth authorization code that can be exchanged for access tokens. This rule may help identify unauthorized use of the VS Code OAuth flow as part of social engineering or credential phishing activity.

Read More

Identifies potential brute-force attempts against Microsoft 365 user accounts by detecting a high number of failed login attempts or login sources within a 30-minute window. Attackers may attempt to brute force user accounts to gain unauthorized access to Microsoft 365 services.

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. 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.

Read More

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.

Read More

Identifies when an excessive number of files are downloaded from OneDrive using OAuth authentication. Adversaries may conduct phishing campaigns to steal OAuth tokens and impersonate users. These access tokens can then be used to download files from OneDrive.

Read More

Identifies a failed OAuth 2.0 token grant attempt for a public client app using client credentials. This event is generated when a public client app attempts to exchange a client credentials grant for an OAuth 2.0 access token, but the request is denied due to the lack of required scopes. This could indicate compromised client credentials in which an adversary is attempting to obtain an access token for unauthorized scopes. This is a New Terms rule where the okta.actor.display_name field value has not been seen in the last 14 days regarding this event.

Read More

This rule detects when a specific Okta actor has multiple device token hashes for a single Okta session. This may indicate an authenticated session has been hijacked or is being used by multiple devices. Adversaries may hijack a session to gain unauthorized access to Okta admin console, applications, tenants, or other resources.

Read More

Detects successful single sign-on (SSO) events to Okta applications from an unrecognized or "unknown" client device, as identified by the user-agent string. This activity may be indicative of exploitation of a vulnerability in Okta's Classic Engine, which could allow an attacker to bypass application-specific sign-on policies, such as device or network restrictions. The vulnerability potentially enables unauthorized access to applications using only valid, stolen credentials, without requiring additional authentication factors.

Read More