O365 Threat Intelligence Suspicious File Detected: threatO365 Tenantrisk_score:502024-09-30version:2
The following analytic identifies when a malicious file is detected within the Microsoft Office 365 ecosystem through the Advanced Threat Protection engine. Attackers may stage and execute malicious files from within the Microsoft Office 365 ecosystem. Any detections from built-in Office 365 capabilities should be monitored and responded to appropriately. Certain premium Office 365 capabilities such as Safe Attachment and Safe Links further enhance these detection and response functions.
O365 Block User Consent For Risky Apps Disabled: auditO365 Tenantrisk_score:302024-09-30version:3
The following analytic detects when the "risk-based step-up consent" security setting in Microsoft 365 is disabled. It monitors Azure Active Directory logs for the "Update authorization policy" operation, specifically changes to the "AllowUserConsentForRiskyApps" setting. This activity is significant because disabling this feature can expose the organization to OAuth phishing threats, allowing users to grant consent to malicious applications. If confirmed malicious, attackers could gain unauthorized access to user data and sensitive information, leading to data breaches and further compromise within the organization.
O365 User Consent Blocked for Risky Application: identityO365 Tenantrisk_score:302024-09-30version:3
The following analytic identifies instances where Office 365 has blocked a user's attempt to grant consent to an application deemed risky or potentially malicious. This detection leverages O365 audit logs, specifically focusing on failed user consent actions due to system-driven blocks. Monitoring these blocked consent attempts is crucial as it highlights potential threats early on, indicating that a user might be targeted or that malicious applications are attempting to infiltrate the organization. If confirmed malicious, this activity suggests that O365's security measures successfully prevented a harmful application from accessing organizational data, warranting immediate investigation.
O365 User Consent Denied for OAuth Application: identityO365 Tenantrisk_score:302024-09-30version:4
The following analytic identifies instances where a user has denied consent to an OAuth application seeking permissions within the Office 365 environment. This detection leverages O365 audit logs, focusing on events related to user consent actions. By filtering for denied consent actions associated with OAuth applications, it captures instances where users have actively rejected permission requests. This activity is significant as it may indicate users spotting potentially suspicious or unfamiliar applications. If confirmed malicious, it suggests an attempt by a potentially harmful application to gain unauthorized access, which was proactively blocked by the user.
O365 High Number Of Failed Authentications for User: identityO365 Tenantrisk_score:352024-09-30version:4
The following analytic identifies an O365 account experiencing more than 20 failed authentication attempts within 5 minutes. It uses O365 Unified Audit Logs, specifically "UserLoginFailed" events, to monitor and flag accounts exceeding this threshold. This activity is significant as it may indicate a brute force attack or password guessing attempt. If confirmed malicious, an attacker could gain unauthorized access to the O365 environment, potentially compromising sensitive emails, documents, and other data. Prompt investigation and action are crucial to prevent unauthorized access and data breaches.
O365 Email Security Feature Changed: threatO365 Tenantrisk_score:252024-09-30version:2
The following analytic identifies when specific O365 advanced security settings are altered within the Office 365 tenant. If an attacker successfully disables O365 security settings, they can operate within the tenant with reduced risk of detection. This can lead to unauthorized data access, data exfiltration, account compromise, or other malicious activities without leaving a detailed audit trail.
O365 SharePoint Malware Detection: threatO365 Tenantrisk_score:752024-09-30version:2
The following analytic identifies when a malicious file is detected within the SharePoint Online ecosystem. Attackers may stage and execute malicious files from within the Microsoft Office 365 ecosystem. Any detections from built-in Office 365 capabilities should be monitored and responded to appropriately. Certain premium Office 365 capabilities further enhance these detection and response functions.
O365 Concurrent Sessions From Different Ips: threatO365 Tenantrisk_score:422024-09-30version:4
The following analytic identifies user sessions in Office 365 accessed from multiple IP addresses, indicating potential adversary-in-the-middle (AiTM) phishing attacks. It detects this activity by analyzing Azure Active Directory logs for 'UserLoggedIn' operations and flags sessions with more than one associated IP address. This behavior is significant as it suggests unauthorized concurrent access, which is uncommon in normal usage. If confirmed malicious, the impact could include data theft, account takeover, and the launching of internal phishing campaigns, posing severe risks to organizational security.
O365 Security And Compliance Alert Triggered: identityO365 Tenantrisk_score:482024-09-30version:4
The following analytic identifies alerts triggered by the Office 365 Security and Compliance Center, indicating potential threats or policy violations. It leverages data from the `o365_management_activity` dataset, focusing on events where the workload is SecurityComplianceCenter and the operation is AlertTriggered. This activity is significant as it highlights security and compliance issues within the O365 environment, which are crucial for maintaining organizational security. If confirmed malicious, these alerts could indicate attempts to breach security policies, leading to unauthorized access, data exfiltration, or other malicious activities.
O365 Multiple AppIDs and UserAgents Authentication Spike: identityO365 Tenantrisk_score:482024-09-30version:4
The following analytic identifies unusual authentication activity in an O365 environment, where a single user account experiences more than 8 authentication attempts using 3 or more unique application IDs and over 5 unique user agents within a short timeframe. It leverages O365 audit logs, focusing on authentication events and applying statistical thresholds. This behavior is significant as it may indicate an adversary probing for multi-factor authentication weaknesses. If confirmed malicious, it suggests a compromised account, potentially leading to unauthorized access, privilege escalation, and data exfiltration. Early detection is crucial to prevent further exploitation.
O365 File Permissioned Application Consent Granted by User: identityO365 Tenantrisk_score:402024-09-30version:3
The following analytic identifies instances where a user in the Office 365 environment grants consent to an application requesting file permissions for OneDrive or SharePoint. It leverages O365 audit logs, focusing on OAuth application consent events. This activity is significant because granting such permissions can allow applications to access, modify, or delete files, posing a risk if the application is malicious or overly permissive. If confirmed malicious, this could lead to data breaches, data loss, or unauthorized data manipulation, necessitating immediate investigation to validate the application's legitimacy and assess potential risks.
O365 Safe Links Detection: threatO365 Tenantrisk_score:402024-09-30version:2
The following analytic detects when any Microsoft Safe Links alerting is triggered. This behavior may indicate when user has interacted with a phishing or otherwise malicious link within the Microsoft Office ecosystem.
High Number of Login Failures from a single source: threatO365 Tenantrisk_score:252024-09-30version:4
The following analytic detects multiple failed login attempts in Office365 Azure Active Directory from a single source IP address. It leverages Office365 management activity logs, specifically AzureActiveDirectoryStsLogon records, aggregating these logs in 5-minute intervals to count failed login attempts. This activity is significant as it may indicate brute-force attacks or password spraying, which are critical to monitor. If confirmed malicious, an attacker could gain unauthorized access to Office365 accounts, leading to potential data breaches, lateral movement within the organization, or further malicious activities using the compromised account.
O365 Excessive SSO logon errors: threatO365 Tenantrisk_score:642024-09-30version:5
The following analytic detects accounts experiencing a high number of Single Sign-On (SSO) logon errors. It leverages data from the `o365_management_activity` dataset, focusing on failed user login attempts with SSO errors. This activity is significant as it may indicate brute-force attempts or the hijacking/reuse of SSO tokens. If confirmed malicious, attackers could potentially gain unauthorized access to user accounts, leading to data breaches, privilege escalation, or further lateral movement within the organization.
O365 Email Suspicious Behavior Alert: threatO365 Tenantrisk_score:902024-09-30version:2
The following analytic identifies when one of O365 the built-in security detections for suspicious email behaviors are triggered. These alerts often indicate that an attacker may have compromised a mailbox within the environment. Any detections from built-in Office 365 capabilities should be monitored and responded to appropriately. Certain premium Office 365 capabilities further enhance these detection and response functions.
O365 Multiple Users Failing To Authenticate From Ip: identityO365 Tenantrisk_score:632024-09-30version:5
The following analytic identifies instances where more than 10 unique user accounts fail to authenticate from a single IP address within a 5-minute window. This detection leverages O365 audit logs, specifically Azure Active Directory login failures (AzureActiveDirectoryStsLogon). Such activity is significant as it may indicate brute-force attacks or password spraying attempts. If confirmed malicious, this behavior suggests an external entity is attempting to breach security by targeting multiple accounts, potentially leading to unauthorized access. Immediate action is required to block or monitor the suspicious IP and notify affected users to enhance their security measures.
O365 Service Principal Privilege Escalation: identityAzure Tenantrisk_score:1002025-01-06version:1
This detection identifies when an Azure Service Principal elevates privileges by adding themself to a new app role assignment.
O365 Email Access By Security Administrator: threatO365 Tenantrisk_score:252024-09-30version:2
The following analytic identifies when a user with sufficient access to O365 Security & Compliance portal uses premium investigation features (Threat Explorer) to directly view email. Adversaries may exploit privileged access with this premium feature to enumerate or exfiltrate sensitive data.
O365 Excessive Authentication Failures Alert: threatO365 Tenantrisk_score:642024-09-30version:4
The following analytic identifies an excessive number of authentication failures, including failed attempts against MFA prompt codes. It uses data from the `o365_management_activity` dataset, focusing on events where the authentication status is marked as failure. This behavior is significant as it may indicate a brute force attack or an attempt to compromise user accounts. If confirmed malicious, this activity could lead to unauthorized access, data breaches, or further exploitation within the environment.
O365 Multi-Source Failed Authentications Spike: identityO365 Tenantrisk_score:422024-10-17version:4
The following analytic identifies a spike in failed authentication attempts within an Office 365 environment, indicative of a potential distributed password spraying attack. It leverages UserLoginFailed events from O365 Management Activity logs, focusing on ErrorNumber 50126. This detection is significant as it highlights attempts to bypass security controls using multiple IP addresses and user agents. If confirmed malicious, this activity could lead to unauthorized access, data breaches, privilege escalation, and lateral movement within the organization. Early detection is crucial to prevent account takeovers and mitigate subsequent threats.
O365 Multiple Failed MFA Requests For User: identityO365 Tenantrisk_score:482024-09-30version:4
The following analytic identifies potential "MFA fatigue" attacks targeting Office 365 users by detecting more than nine Multi-Factor Authentication (MFA) prompts within a 10-minute timeframe. It leverages O365 management activity logs, focusing on Azure Active Directory events with the UserLoginFailed operation, a Success ResultStatus, and an ErrorNumber of 500121. This activity is significant as attackers may exploit MFA fatigue to gain unauthorized access by overwhelming users with repeated MFA requests. If confirmed malicious, this could lead to data breaches, unauthorized data access, or further compromise within the O365 environment. Immediate investigation is crucial.
O365 Mail Permissioned Application Consent Granted by User: identityO365 Tenantrisk_score:402024-09-30version:3
The following analytic identifies instances where a user grants consent to an application requesting mail-related permissions within the Office 365 environment. It leverages O365 audit logs, specifically focusing on events related to application permissions and user consent actions. This activity is significant as it can indicate potential security risks, such as data exfiltration or spear phishing, if malicious applications gain access. If confirmed malicious, this could lead to unauthorized data access, email forwarding, or sending malicious emails from the compromised account. Validating the legitimacy of the application and consent context is crucial to prevent data breaches.
