Detections

Explore public detection logic contributed by the community across SIEM and rule languages.

3,004 detections

The following analytic identifies when an O365 email account sends and then hard deletes an email to an external recipient within a short period (within 1 hour). This behavior may indicate a compromised account where the threat actor is attempting to remove forensic artifacts or evidence of exfiltration activity. This behavior is often seen when threat actors want to reduce the probability of detection by the compromised account owner.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0041
The following analytic identifies the creation of new email forwarding rules in an Office 365 environment via the UpdateInboxRules operation. It leverages Office 365 management activity events to detect rules that forward emails to external recipients by examining the OperationProperties for specific forwarding actions. This activity is significant as it may indicate unauthorized email redirection, potentially leading to data exfiltration. If confirmed malicious, attackers could intercept sensitive communications, leading to data breaches and information leakage.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0041
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.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0041
The analytic detects the disablement of security steps in a CircleCI pipeline. This activity is significant because disabling security steps can introduce vulnerabilities, unauthorized changes, or malicious code into the pipeline. If confirmed malicious, this could lead to potential attacks, data breaches, or compromised infrastructure. The rule leverages CircleCI logs, using field renaming, joining, and statistical analysis to identify instances where mandatory security steps are not executed. Investigation should focus on reviewing job names, commit details, and user information associated with the disablement, and examining any relevant artifacts and concurrent processes.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0040
The analytic detects unauthorized access attempts to Kubernetes by analyzing Kubernetes audit logs. It identifies anomalies in access patterns by examining the source of requests and their response statuses. This activity is significant for a SOC as it may indicate an attacker attempting to infiltrate the Kubernetes environment. If confirmed malicious, such access could lead to unauthorized control over Kubernetes resources, potentially compromising sensitive systems or data within the cluster.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0040
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.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0040
This rule detects modifications to the Access Control List (ACL) of the domain root object in Active Directory. Such modifications are significant and can have a high impact on the security of the Active Directory environment. The rule specifically looks for EventCode 5136 (A directory service object was modified) where the ObjectClass is 'domainDNS'. It then parses the old and new ACL values to identify specific changes, including the type of access control entry (ACE), flags, access rights, and the security identifier (SID) of the user or group affected. The rule also attempts to resolve SIDs to user or group names for better readability. Microsoft guidance suggests that all changes at this level should be reviewed.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0040
The following analytic identifies the execution of `net.exe` with command-line arguments used to query global, local and domain groups. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line arguments. This activity is significant as it indicates potential reconnaissance efforts by adversaries to enumerate local or domain groups, which is a common step in Active Directory or privileged accounts discovery. If confirmed malicious, this behavior could allow attackers to gain insights into the domain structure, aiding in further attacks such as privilege escalation or lateral movement.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0040
This analytic detects an increase in modifications to AD user objects. A large volume of changes to user objects can indicate potential security risks, such as unauthorized access attempts, impairing defences or establishing persistence. By monitoring AD logs for unusual modification patterns, this detection helps identify suspicious behavior that could compromise the integrity and security of the AD environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1040
The following analytic detects `StopLogging` events within AWS CloudTrail logs, a critical action that adversaries may use to evade detection. By halting the logging of their malicious activities, attackers aim to operate undetected within a compromised AWS environment. This detection is achieved by monitoring for specific CloudTrail log entries that indicate the cessation of logging activities. Identifying such behavior is crucial for a Security Operations Center (SOC), as it signals an attempt to undermine the integrity of logging mechanisms, potentially allowing malicious activities to proceed without observation. The impact of this evasion tactic is significant, as it can severely hamper incident response and forensic investigations by obscuring the attacker's actions.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0039
The analytic detects `PutBucketLifecycle` events in AWS CloudTrail logs where a user sets a lifecycle rule for an S3 bucket with an expiration period of fewer than three days. This activity is significant because attackers may use it to delete CloudTrail logs quickly, thereby evading detection and impairing forensic investigations. If confirmed malicious, this could allow attackers to cover their tracks, making it difficult to trace their actions and respond to the breach effectively.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0039
The following analytic identifies the assignment of elevated mailbox permissions in an Office 365 environment via the Add-MailboxPermission operation. It leverages logs from the Exchange workload in the o365_management_activity data source, focusing on permissions such as FullAccess, ChangePermission, or ChangeOwner. This activity is significant as it indicates potential unauthorized access or control over mailboxes, which could lead to data exfiltration or privilege escalation. If confirmed malicious, attackers could gain extensive access to sensitive email data and potentially manipulate mailbox settings, posing a severe security risk.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0039
The following analytic identifies instances where read permissions are assigned to mailbox folders within an Office 365 environment. It leverages the `o365_management_activity` data source, specifically monitoring the `ModifyFolderPermissions` and `AddFolderPermissions` operations, while excluding Calendar, Contacts, and PersonMetadata objects. This activity is significant as unauthorized read permissions can lead to data exposure and potential information leakage. If confirmed malicious, an attacker could gain unauthorized access to sensitive emails, leading to data breaches and compromising the confidentiality of organizational communications.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0039
The following analytic detects instances where a user has initiated an eDiscovery search or exported a PST file in an Office 365 environment. It leverages Office 365 management activity logs, specifically filtering for events under ThreatManagement with the name "eDiscovery search started or exported." This activity is significant as it may indicate data exfiltration attempts or unauthorized access to sensitive information. If confirmed malicious, it suggests an attacker or insider threat is attempting to gather or exfiltrate data, potentially leading to data breaches, loss of intellectual property, or unauthorized access to confidential communications. Immediate investigation is required.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0039
The following analytic detects the temporary addition of a global catalog SPN or a DRS RPC SPN to an Active Directory computer object, indicative of a potential DCShadow attack. This detection leverages EventCode 5136 from the `wineventlog_security` data source, focusing on specific SPN attribute changes. This activity is significant as DCShadow attacks allow attackers with privileged access to register rogue Domain Controllers, enabling unauthorized changes to the AD infrastructure. If confirmed malicious, this could lead to unauthorized replication of changes, including credentials and keys, compromising the entire domain's security.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1039
The following analytic identifies the creation of a new AWS IAM policy version that allows access to all resources. It detects this activity by analyzing AWS CloudTrail logs for the CreatePolicyVersion event with a policy document that grants broad permissions. This behavior is significant because it violates the principle of least privilege, potentially exposing the environment to misuse or abuse. If confirmed malicious, an attacker could gain extensive access to AWS resources, leading to unauthorized actions, data exfiltration, or further compromise of the AWS environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0038
The analytic detects the assignment of the Azure AD Global Administrator role to a user. This activity is significant because the Global Administrator role grants extensive access to data, resources, and settings, similar to a Domain Administrator in traditional AD environments. If confirmed malicious, this could allow an attacker to establish persistence, escalate privileges, and potentially gain control over Azure resources, posing a severe security risk.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0038
The following analytic detects the assignment of the Privileged Authentication Administrator role to an Azure AD user. It leverages Azure Active Directory audit logs to identify when this specific role is assigned. This activity is significant because users in this role can set or reset authentication methods for any user, including those in privileged roles like Global Administrators. If confirmed malicious, an attacker could change credentials and assume the identity and permissions of high-privilege users, potentially leading to unauthorized access to sensitive information and critical configurations.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0038
The analytic detects the addition of a new owner to a Service Principal within an Azure AD tenant. This activity is significant because Service Principals do not support multi-factor authentication or conditional access policies, making them a target for adversaries seeking persistence or privilege escalation. If confirmed malicious, this activity could allow attackers to maintain access to the Azure AD environment with single-factor authentication, potentially leading to unauthorized access and control over critical resources.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0038
The following analytic detects when two-factor authentication (2FA) requirements are disabled in GitHub Enterprise. The detection monitors GitHub Enterprise audit logs for 2FA requirement changes by tracking actor details, organization information, and associated metadata. For a SOC, identifying disabled 2FA requirements is critical as it could indicate attempts to weaken account security controls. Two-factor authentication is a fundamental security control that helps prevent unauthorized access even if passwords are compromised. Disabling 2FA requirements could allow attackers to more easily compromise accounts through password-based attacks. The impact of disabled 2FA includes increased risk of account takeover, potential access to sensitive code and intellectual property, and compromise of the software supply chain. This activity could be part of a larger attack chain where an adversary first disables security controls before attempting broader account compromises.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1038
This analytic identifies instances where the Mail.Read Graph API permissions are granted to an application registration within an Office 365 tenant. It leverages O365 audit logs, specifically events related to changes in application permissions within the AzureActiveDirectory workload. This activity is significant because the Mail.Read permission allows applications to access and read all emails within a user's mailbox, which often contain sensitive or confidential information. If confirmed malicious, this could lead to data exfiltration, spear-phishing attacks, or further compromise based on the information gathered from the emails.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0038
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