Detections

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

4,311 detections

This rule detects the creation of a Volume Shadow Copy using PowerShell, specifically looking for the `Win32_ShadowCopy` WMI class and the `.Create()` method with the `ClientAccessible` parameter. Adversaries often use Volume Shadow Copies to access or copy the Active Directory domain database (NTDS.dit) to steal credential information, or other sensitive data from the local system.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0019
The following analytic identifies unauthorized Active Directory replication requests initiated from non-domain controller locations. It leverages EventCode 4662 to detect when a computer account with replication permissions creates a handle to domainDNS, filtering out known domain controller IP addresses. This activity is significant as it may indicate a DCSync attack, where an attacker with privileged access can request password hashes for any or all users within the domain. If confirmed malicious, this could lead to unauthorized access to sensitive information and potential full domain compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1041
Detects the execution of remote access, tunneling, and credential access tools from suspicious directories. This rule specifically targets tools commonly abused by threat actors like Scattered Spider, such as AnyDesk, TeamViewer, ngrok, Teleport, Tailscale, and Mimikatz, when executed from user-writable or temporary folders. It excludes legitimate installations in standard Program Files directories to reduce false positives.
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Mitchell V@mvani
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Detections.ai Community
1 year ago
230366
This detection identifies interactive sign-ins from countries that a user has not accessed from in the past 30 days, based on successful logins. It highlights unusual geographic access patterns, such as remote work via VPNs, possible account compromise, or other travel-related anomalies.

Only interactive sign-ins are included to reduce noise from background service logins and token refreshes.

Recommended Extensions:

1. Trusted Applications Watchlist
Use a Sentinel watchlist (e.g., `TrustedAppsWatchlist`) to maintain known or expected applications (like SAP Cloud Identity Services, Microsoft Teams, Outlook Mobile) that frequently authenticate across multiple countries or devices. This helps suppress expected behavior and avoids alert fatigue.

2. Workation / Remote User Watchlist
Create a watchlist (e.g., `WorkationUsers`) with UPNs or user aliases of employees who are temporarily working abroad or from rotating locations. This allows legitimate, location-shifting activity to be filtered out of alerting, reducing false positives during travel seasons or flexible remote work arrangements.
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Michael Fajkus@MilesDyson
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Detections.ai Community
1 year ago
81102
This detection identifies access to sensitive system and configuration files on an ESXi host, including authentication data, service configurations, and VMware-specific management settings. Interaction with these files may indicate adversary reconnaissance, credential harvesting, or preparation for privilege escalation, lateral movement, or persistence.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
4084
This query detects Kerberos pre-authentication attempts where the captured source address is external.
You can tweak and remove the RFC's to also look at internal requests, but expect some noise.
In addition, you might want to tweak the counter.
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David Dvir@BizzareC0ntact
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Detections.ai Community
1 year ago
80237
Detects NTLM successful network logons where the source and destination workstations are the same, excluding loopback addresses. This behavior can be indicative of NTLM relay attacks where an attacker relays authentication from a victim to the victim's own machine, or other forms of NTLM abuse.
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R W@shiftyroot
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Detections.ai Community
1 year ago
53112
This detection identifies suspicious authentication failure patterns that may indicate brute-force attacks. It detects four common scenarios:

- Repeated failed login attempts to a single account from a single IP address.
- Distributed login attempts to a single account from multiple IPs.
- A single IP address targeting multiple accounts.
- Broad-scale attempts involving multiple accounts and multiple IPs in a short timeframe.

This rule focuses on failed login attempts only and is intended for early brute-force detection and threat hunting.

Note:
Consider tuning the TimeWindow (default: 10 minutes) and Threshold (default: 5 attempts) values to reflect your organization’s normal login activity. A more permissive or stricter threshold may be necessary depending on your environment (e.g., high-traffic services, mobile users, VPNs).

Includes both a readable union-based version and a compact case()-based variant for performance-conscious deployments.
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Michael Fajkus@MilesDyson
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Detections.ai Community
1 year ago
30146
This rule detects attempts by scripting language interpreters (Node.js, Python, PowerShell) to access sensitive browser credential files such as 'Login Data', 'Web Data', and 'Cookies' from Chrome and Brave browser user data directories. It also includes specific file paths that might be associated with known browser extensions or malware that target these files. This activity is indicative of credential dumping or information stealing.
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R W@shiftyroot
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Detections.ai Community
1 year ago
2298
Detects when a process loads UIAutomationCore.dll, which may indicate abuse of Microsoft's UI Automation framework. This technique has been observed in Coyote malware for credential theft from banking applications and cryptocurrency exchanges. The rule monitors for processes that load the UI Automation Core library, which enables automated interaction with UI elements.
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Prashanth P@prashanthblogs
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Detections.ai Community
1 year ago
0127
Detects when a user's phone authentication method is changed or added, followed shortly by a successful MFA-based sign-in for that same user. This pattern can indicate a SIM swap attack where an adversary socially engineers a helpdesk or convinces a mobile carrier to port a user's number to an adversary-controlled SIM card. This allows the adversary to intercept MFA codes sent via SMS or phone call and gain unauthorized access.
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ravi vaghasiya@ravivaghasiya
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Detections.ai Community
1 year ago
142128
Detects suspicious reuse of NTLM authentication hashes by the same user account across multiple hosts within a short time window. This behavior may indicate lateral movement techniques such as pass-the-hash attacks or credential replay.
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Michael Fajkus@MilesDyson
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Detections.ai Community
1 year ago
281179
Detects potential Unicode-based homograph attacks by scanning for non-ASCII characters in both DeviceNetworkEvents.RemoteUrl and EmailUrlInfo.Url. These attacks leverage visually deceptive domain names—using characters from non-Latin scripts (e.g., Cyrillic "а" instead of Latin "a")—to mimic legitimate sites and deceive users.

The detection covers both network activity and email delivery paths, helping uncover phishing attempts, credential harvesting links, or other malicious redirects.

Recommendation: If available, include telemetry from DNS logs (e.g., DnsEvents) and firewall/proxy logs to improve detection coverage and correlate threats across multiple layers of the kill chain.
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Michael Fajkus@MilesDyson
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Detections.ai Community
1 year ago
12055
The following analytic detects the usage of specific Exchange PowerShell modules, such as New-MailboxExportRequest, New-ManagementRoleAssignment, New-MailboxSearch, and Get-Recipient. It leverages PowerShell Script Block Logging (EventCode 4104) to identify these commands. This activity is significant because these modules can be exploited by adversaries who have gained access via ProxyShell or ProxyNotShell vulnerabilities. If confirmed malicious, attackers could export mailbox contents, assign management roles, conduct mailbox searches, or view recipient objects, potentially leading to data exfiltration, privilege escalation, or unauthorized access to sensitive information.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1063
Detects the reconfiguration of a virtual machine where a virtual disk (.vmdk) from a different, often critical, VM is attached. This is a key tactic used by threat actors like UNC3944 to perform offline credential theft by mounting a Domain Controller's disk to a staging VM to access the NTDS.dit file.
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Kaung Khant Ko@kaungkhantko
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Detections.ai Community
1 year ago
52131
The following analytic identifies command-line activity that searches for files related to password manager software, such as "*.kdbx*" and "*credential*". It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs. This activity is significant because attackers often target password manager databases to extract stored credentials, which can be used for further exploitation. If confirmed malicious, this behavior could lead to unauthorized access to sensitive information, enabling attackers to escalate privileges, move laterally, or exfiltrate critical data.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2045
The following analytic identifies suspicious Cmdlet usage in Exchange Management logs, focusing on commands like New-MailboxExportRequest and New-ManagementRoleAssignment. It leverages EventCode 1 and specific Message patterns to detect potential ProxyShell and ProxyNotShell abuse. This activity is significant as it may indicate unauthorized access or manipulation of mailboxes and roles, which are critical for maintaining email security. If confirmed malicious, attackers could export mailbox data, assign new roles, or search mailboxes, leading to data breaches and privilege escalation.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2042
This detection identifies instances where the diskshadow.exe utility is executed by a privileged user shortly after a successful logon. diskshadow.exe is a legitimate tool often abused by attackers for shadow copy manipulation and data exfiltration. Monitoring its use by privileged accounts helps identify potential malicious activity.
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Michael Fajkus@MilesDyson
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Detections.ai Community
1 year ago
2142
The following analytic detects the execution of the `Get-ADUser` PowerShell cmdlet with parameters indicating a search for domain accounts with Kerberos Pre-Authentication disabled. It leverages PowerShell Script Block Logging (EventCode=4104) to identify this specific activity. This behavior is significant because discovering accounts with Kerberos Pre-Authentication disabled can allow adversaries to perform offline password cracking. If confirmed malicious, this activity could lead to unauthorized access to user accounts, potentially compromising sensitive information and escalating privileges within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
3054
The following analytic identifies the addition and quick deletion of a Service Principal Name (SPN) to a domain account within 5 minutes. This detection leverages EventCode 5136 from the Windows Security Event Log, focusing on changes to the servicePrincipalName attribute. This activity is significant as it may indicate an attempt to perform Kerberoasting, a technique used to crack the cleartext password of a domain account offline. If confirmed malicious, this could allow an attacker to gain unauthorized access to sensitive information or escalate privileges within the domain environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0048
This analytic detects the addition of a Service Principal Name (SPN) to a domain account. It leverages Windows Event Code 5136 and monitors changes to the servicePrincipalName attribute. This activity is significant because it may indicate an attempt to perform Kerberoasting, a technique where attackers extract and crack service account passwords offline. If confirmed malicious, this could allow an attacker to obtain cleartext passwords, leading to unauthorized access and potential lateral movement within the domain environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
6046
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