Detections

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

1,061 detections

The analytic detects attempts to authenticate using the built-in local Administrator account across more than 30 endpoints within a 5-minute window. It leverages Windows Event Logs, specifically events 4625 (failed logon) and 4624 (successful logon), to identify this behavior. This activity is significant as it may indicate an adversary attempting to validate stolen local credentials across multiple hosts, potentially leading to privilege escalation. If confirmed malicious, this could allow the attacker to gain widespread access and control over numerous systems within the network, posing a severe security risk.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
3066
The following analytic detects high-risk sign-in attempts against Azure Active Directory, identified by Azure Identity Protection. It leverages the RiskyUsers and UserRiskEvents log categories from Azure AD events ingested via EventHub. This activity is significant as it indicates potentially compromised accounts, flagged by heuristics and machine learning. If confirmed malicious, attackers could gain unauthorized access to sensitive resources, leading to data breaches or further exploitation within the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0065
This analytic identifies suspicious use of a session cookie by detecting multiple client values (IP, User Agent, etc.) changing for the same Device Token associated with a specific user. It leverages policy evaluation events from successful authentication logs in Okta. This activity is significant as it may indicate an adversary attempting to reuse a stolen web session cookie, potentially bypassing authentication mechanisms. If confirmed malicious, this could allow unauthorized access to user accounts, leading to data breaches or further exploitation within the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2063
The analytic detects an Azure AD account with concurrent sessions originating from multiple unique IP addresses within a 5-minute window. It leverages Azure Active Directory NonInteractiveUserSignInLogs to identify this behavior by analyzing successful authentication events and counting distinct source IPs. This activity is significant as it may indicate session hijacking, where an attacker uses stolen session cookies to access corporate resources from a different location. If confirmed malicious, this could lead to unauthorized access to sensitive information and potential data breaches.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2061
This analytic identifies an AWS IAM account with concurrent sessions originating from more than one unique IP address within a 5-minute span. This detection leverages AWS CloudTrail logs, specifically the `DescribeEventAggregates` API call, to identify multiple IP addresses associated with the same user session. This behavior is significant as it may indicate a session hijacking attack, where an adversary uses stolen session cookies to access AWS resources from a different location. If confirmed malicious, this activity could allow unauthorized access to sensitive corporate resources, leading to potential data breaches or further exploitation.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2059
The analytic identifies AWS console login attempts by users from a new region. It leverages AWS CloudTrail events and compares current login regions against a baseline of previously seen regions for each user. This activity is significant as it may indicate unauthorized access attempts or compromised credentials. If confirmed malicious, an attacker could gain unauthorized access to AWS resources, potentially leading to data breaches, resource manipulation, or further lateral movement within the cloud environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0057
The analytic detects multiple failed attempts to access applications in Okta, potentially indicating the reuse of a stolen web session cookie. It leverages Okta logs to evaluate policy and SSO events, aggregating data by user, session, and IP. The detection triggers when more than half of the app sign-on attempts are unsuccessful across multiple applications. This activity is significant as it may indicate an attempt to bypass authentication mechanisms. If confirmed malicious, it could lead to unauthorized access to sensitive applications and data, posing a significant security risk.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1055
The following analytic identifies AWS console login events by users from a new country. It leverages AWS CloudTrail events and compares them against a lookup file of previously seen users and their login locations. This activity is significant because logins from new countries can indicate potential unauthorized access or compromised accounts. If confirmed malicious, this could lead to unauthorized access to AWS resources, data exfiltration, or further exploitation within the AWS environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0055
The following analytic detects CrowdStrike alerts for weak password policy violations, identifying instances where passwords do not meet the required security standards. These alerts highlight potential vulnerabilities that could be exploited by attackers, emphasizing the need for stronger password practices. Addressing these alerts promptly helps to enhance overall security and protect sensitive information from unauthorized access.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1052
The analytic detects unusual authentication activity in Azure AD, specifically when a single user account has over 8 authentication attempts using 3+ unique application IDs and 5+ unique user agents within a short period. This behavior is significant as it may indicate an adversary probing for MFA requirements or attempting to bypass MFA. If confirmed malicious, it suggests a compromised account, potentially leading to further exploitation, lateral movement, and data exfiltration. Early detection is crucial to prevent substantial harm.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0051
The following analytic detects changes to computer accounts using an anonymous logon. It leverages Windows Security Event Codes 4742 (Computer Change) and 4624 (Successful Logon) with the TargetUserName set to "ANONYMOUS LOGON" and LogonType 3. This activity is significant because anonymous logons should not typically be modifying computer accounts, indicating potential unauthorized access or misconfiguration. If confirmed malicious, this could allow an attacker to alter computer accounts, potentially leading to privilege escalation or persistent access within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
3149
This analytic detects when an unusual number of NTLM authentications is attempted by the same source. This activity generally results when an attacker attempts to brute force, password spray, or otherwise authenticate to a domain joined Windows device using an NTLM based process/attack. This same activity may also generate a large number of EventID 4776 events in as well.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0047
The following analytic detects CrowdStrike alerts for non-admin accounts with duplicate password risk, identifying instances where multiple non-admin users share the same password. This practice weakens security and increases the potential for unauthorized access. Addressing these alerts is essential to ensure each user account has a unique, strong password, thereby enhancing overall security and protecting sensitive information.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0045
The analytic identifies an AWS IAM account with concurrent sessions originating from more than one unique IP address within a 5-minute window. It leverages AWS CloudTrail logs, specifically the `DescribeEventAggregates` event, to detect this behavior. This activity is significant as it may indicate a session hijacking attack, where an adversary uses stolen session cookies to access AWS resources from a different location. If confirmed malicious, this could allow unauthorized access to sensitive corporate resources, leading to potential data breaches or further exploitation within the AWS environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0044
The analytic detects when a device is the target of numerous NTLM authentications using a null domain. This activity generally results when an attacker attempts to brute force, password spray, or otherwise authenticate to a domain joined Windows device from a non-domain device. This activity may also generate a large number of EventID 4776 events in tandem, however these events will not indicate the attacker or target device.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1044
The analytic detects patterns of successful and failed Okta MFA push attempts to identify potential MFA exhaustion attacks. It leverages Okta event logs, specifically focusing on push verification events, and uses statistical evaluations to determine suspicious activity. This activity is significant as it may indicate an attacker attempting to bypass MFA by overwhelming the user with push notifications. If confirmed malicious, this could lead to unauthorized access, compromising the security of the affected accounts and potentially the entire environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2043
The following analytic detects an attempt to disable multi-factor authentication (MFA) for a Google Cloud Platform (GCP) user. It leverages Google Workspace Admin log events, specifically the UNENROLL_USER_FROM_STRONG_AUTH command. This activity is significant because disabling MFA can allow an adversary to maintain persistence within the environment using a compromised account without raising suspicion. If confirmed malicious, this action could enable attackers to bypass additional security layers, potentially leading to unauthorized access, data exfiltration, or further exploitation of the compromised account.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0043
This analytic identifies new login attempts to network routers. It uses authentication logs from the ES Assets and Identity Framework, specifically looking for assets categorized as 'router'. The rule flags connections that have not been observed in the past 30 days. Unauthorized access to routers is critical as it can lead to network disruptions, data interception, or further compromise of the network infrastructure.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0041
The analytic identifies discrepancies between the source and response events for Okta Verify Push requests, indicating potential suspicious behavior. It leverages Okta System Log events, specifically `system.push.send_factor_verify_push` and `user.authentication.auth_via_mfa` with the factor "OKTA_VERIFY_PUSH." The detection groups events by SessionID, calculates the ratio of successful sign-ins to push requests, and checks for session roaming and new device/IP usage. This activity is significant as it may indicate push spam or unauthorized access attempts. If confirmed malicious, attackers could bypass MFA, leading to unauthorized access to sensitive systems.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
3041
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.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0041
This analytic detects an unusual number of NTLM authentication attempts by a single user account against multiple distinct destinations. This behavior is indicative of an attacker performing brute-force attacks, password spraying, or other NTLM-based authentication attacks to gain access to numerous domain-joined Windows devices. Such activity may also generate a high volume of Event ID 4776 events.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0041
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