Detections

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

829 detections

The following analytic detects the disabling of audit policies on a domain controller. It leverages EventCode 4719 from Windows Security Event Logs to identify changes where success or failure auditing is removed. This activity is significant as it suggests an attacker may have gained access to the domain controller and is attempting to evade detection by tampering with audit policies. If confirmed malicious, this could lead to severe consequences, including data theft, privilege escalation, and full network compromise. Immediate investigation is required to determine the source and intent of the change.
Splunk Security@SplunkSecurity
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Splunk Security Content
25 days ago
2904
Detects Active Directory DCSync replication requests by monitoring for Event ID 4662 associated with DS-Replication-Get-Changes or DS-Replication-Get-Changes-All extended rights. The rule triggers when these rights are requested by an entity (subject) originating from a host that is not recognized as a Domain Controller.
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Ibrahim Saud@tektrix
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Detections.ai Community
30 days ago
27013
The following analytic detects a user account (non-machine account) adding or removing a servicePrincipalName (SPN) on a computer object in Active Directory, via Windows Security Event 5136.
In normal AD operations, SPN values on computer objects are managed exclusively by the computer account itself (during domain join or name change), by Domain Controllers during replication, or by the SYSTEM/NETWORK SERVICE context — all of which appear as accounts ending in the dollar sign ($) convention.
A named user account writing to the servicePrincipalName attribute of a computer object is anomalous and may indicate an attacker with delegated WriteProperty rights over computer accounts performing SPN manipulation.
Splunk Security@SplunkSecurity
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Splunk Security Content
25 days ago
703
This detection identifies an Active Directory access-control list (ACL) modification event, which applies the minimum required extended rights to perform the DCShadow attack.
Splunk Security@SplunkSecurity
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Splunk Security Content
25 days ago
003
The following analytic detects the addition of permissions required for a DCSync attack, specifically DS-Replication-Get-Changes, DS-Replication-Get-Changes-All, and DS-Replication-Get-Changes-In-Filtered-Set. It leverages EventCode 5136 from the Windows Security Event Log to identify when these permissions are granted. This activity is significant because it indicates potential preparation for a DCSync attack, which can be used to replicate AD objects and exfiltrate sensitive data. If confirmed malicious, an attacker could gain extensive access to Active Directory, leading to severe data breaches and privilege escalation.
Splunk Security@SplunkSecurity
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Splunk Security Content
25 days ago
103
The following analytic detects a user account modifying its own userPrincipalName (UPN) to match the sAMAccountName of another account via Windows Security Event 4738.
This is the setup step of the ResetNightmare attack (CVE-2026-27912), where an attacker with WriteProperty rights on their own UPN attribute spoofs their identity to a target account.
The KDC then resolves a ptype=10 (NT-ENTERPRISE) Kerberos pre-authentication request against the spoofed UPN, issuing a kadmin/changepw TGT that can be used to change the target account's password via kpasswd (port 464).
Event 4738 is generated when a user account attribute is changed. This analytic filters to events where the SubjectUserSid equals the TargetSid (self-modification), the new UPN value is not a standard UPN (no @ sign), and the value is not a Windows placeholder.
A non-UPN value set on one's own account is anomalous and has no legitimate administrative use case.
Splunk Security@SplunkSecurity
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Splunk Security Content
29 days ago
507
This detection monitors the addition of the following ACLs to an Active Directory group object: "Full control", "All extended rights", "All validated writes", "Create all child objects", "Delete all child objects", "Delete subtree", "Delete", "Modify permissions", "Modify owner", and "Write all properties". Such modifications can indicate potential privilege escalation or malicious activity. Immediate investigation is recommended upon alert.
Splunk Security@SplunkSecurity
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Splunk Security Content
25 days ago
102
The following analytic identifies when the SID of a privileged user is added to the SID History attribute of another user. It leverages Windows Security Event Codes 4742 and 4738, combined with identity lookups, to detect this activity. This behavior is significant as it may indicate an attempt to abuse SID history for unauthorized access across multiple domains. If confirmed malicious, this activity could allow an attacker to escalate privileges or maintain persistent access within the environment, posing a significant security risk.
Splunk Security@SplunkSecurity
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Splunk Security Content
25 days ago
002
The following analytic identifies potential Kerberos ticket forging attacks, specifically the Diamond Ticket attack. This is detected when a user logs into a host and the GroupMembership field in event 4627 indicates a privileged group (e.g., Domain Admins), but the user does not actually belong to that group in the directory service. The detection leverages Windows Security Event Log 4627, which logs account logon events. The analytic cross-references the GroupMembership field from the event against a pre-populated lookup of actual group memberships. Its crucial to note that the accuracy and effectiveness of this detection heavily rely on the users diligence in populating and regularly updating this lookup table. Any discrepancies between the events GroupMembership and the lookup indicate potential ticket forging. Kerberos ticket forging, especially the Diamond Ticket attack, allows attackers to impersonate any user and potentially gain unauthorized access to resources. By forging a ticket that indicates membership in a privileged group, an attacker can bypass security controls and gain elevated privileges. Detecting such discrepancies in group memberships during logon events can be a strong indicator of this attack in progress, making it crucial for security teams to monitor and investigate. If validated as a true positive, this indicates that an attacker has successfully forged a Kerberos ticket and may have gained unauthorized access to critical resources, potentially with elevated privileges.
Splunk Security@SplunkSecurity
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Splunk Security Content
25 days ago
002
Detects anomalous authentication patterns where a single source IP targets a high number of unique user accounts with failed authentication attempts over a rolling window. By filtering out SSO/Federated methods and specific service account patterns, this rule isolates low-and-slow brute-force or password-spraying activities designed to evade standard account lockout mechanisms.
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Ankit Mehta@Secvyn
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Detections.ai Community
30 days ago
006
ACL deletion performed on the domain root object, significant AD change with high impact. Following MS guidance all changes at this level should be reviewed. Drill into the logonID within EventCode 4624 for information on the source device during triage.
Splunk Security@SplunkSecurity
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Splunk Security Content
25 days ago
001
ACL modification performed on the domain root object, significant AD change with high impact. Following MS guidance all changes at this level should be reviewed. Drill into the logonID within EventCode 4624 for information on the source device during triage.
Splunk Security@SplunkSecurity
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Splunk Security Content
25 days ago
001
This detection identifies when a a new client side extension is added to an Active Directory Group Policy using the Group Policy Management Console.
Splunk Security@SplunkSecurity
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Splunk Security Content
25 days ago
001
Detects interactive RDP logons (LogonType 10) occurring on domain controllers or VDI authentication servers where the originating workstation name follows naming conventions associated with VDI/virtual-desktop environments. This pattern is indicative of potential lateral movement, where an adversary pivots from a compromised user VDI instance directly to sensitive infrastructure, bypassing established administrative jump box protocols.
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Ankit Mehta@Secvyn
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Detections.ai Community
30 days ago
204
This rule detects suspicious NTLM network logon events (Logon Type 3) involving privileged accounts that do not have corresponding Kerberos authentication events (4768/4769) in the preceding hour. The detection specifically triggers when a single account logs into two or more distinct hosts within a 15-minute window, which is indicative of lateral movement using compromised credentials or Pass-the-Hash techniques.
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Ibrahim Saud@tektrix
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Detections.ai Community
30 days ago
304
Detects the execution of common enumeration tools and commands often associated with ransomware-precursor behavior. This includes the use of AdFind, dsquery, net.exe, and nltest for domain account, group, and trust discovery, as well as the execution of BloodHound/SharpHound collection activities.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
204
Detects the execution of known Active Directory reconnaissance tools, specifically AdFind and SharpHound/BloodHound. These tools are commonly used by adversaries to enumerate domain objects, users, computers, groups, and trusts, which are essential precursors to further lateral movement and privilege escalation within a domain environment.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
104
Detects potential lateral movement by identifying NTLM authentication (Logon Type 3) to administrative network shares (ADMIN$, C$, IPC$) or high-frequency access to multiple hosts by the same user, which may indicate credential abuse or lateral movement attempts.
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Ibrahim Saud@tektrix
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Detections.ai Community
30 days ago
103
This rule detects attempts to steal the Active Directory database (ntds.dit) and associated security files by creating volume shadow copies using native Windows utilities like ntdsutil, vssadmin, or wmic. It also monitors for direct file system access or creation attempts related to these sensitive database files within shadow copy paths.
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Ibrahim Saud@tektrix
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Detections.ai Community
30 days ago
003
Detects potential Pass-the-Hash (PtH) activity where a single user account performs NTLM Type 3 (network) authentications to three or more unique destination hosts within a 10-minute window, excluding service account activity (trailing $). This pattern is consistent with an adversary moving laterally across a network using harvested NTLM hashes.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
103
Detects anomalous Kerberos TGT (4768) or TGS (4769) requests where the ticket lifetime exceeds typical domain policy (10 hours), or where the KRBTGT account is explicitly referenced as the target, both of which are high-fidelity indicators of Golden Ticket forgery attacks.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
003
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