Detections

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

4,918 detections

This rule detects when a user is added to the local 'admin' group on a macOS system using either the `dscl` or `dseditgroup` command-line utilities. It specifically looks for command-line arguments indicative of adding a user to the 'admin' group. There is a whitelist for legitimate MDM solutions like 'jamfmanager' to reduce false positives.
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Benjamin Zulliger@benscha
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Detections.ai Community
1 year ago
231368
This rule detects failed user login attempts within Bitbucket. It specifically looks for audit events categorized as 'Authentication' with the action 'User login failed'. This type of event can indicate various activities, including legitimate users mistyping passwords, or malicious actors attempting to brute-force credentials or perform credential stuffing attacks against Bitbucket accounts.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0032
This rule detects when Okta identifies new or unusual activity within the Admin Console. It specifically looks for 'policy.evaluate_sign_on' events targeting the 'Okta Admin Console' where Okta's internal heuristics (debugcontext.debugdata.behaviors or debugcontext.debugdata.logonlysecuritydata) flag the activity as 'POSITIVE' for unusual behavior. This can indicate an adversary attempting to gain or maintain access to administrative functions, or an administrator performing actions that are outside their typical patterns.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0032
This rule detects when Okta FastPass successfully identifies and prevents an authentication attempt originating from a known phishing site. It specifically looks for Okta System Log events where the outcome reason is 'FastPass declined phishing attempt', the outcome result is 'FAILURE', and the event type is 'user.authentication.auth_via_mfa'. This indicates that a user attempted to authenticate via MFA, but Okta FastPass intervened due to a detected phishing attempt.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0031
Detects cast exceptions in Windows Server Update Services (WSUS) application logs that highly indicate exploitation attempts of CVE-2025-59287, a deserialization vulnerability in WSUS. The rule specifically looks for `System.InvalidCastException` and `System.Windows.Data.ObjectDataProvider` along with `Unable to cast object of type` and `System.Windows.Media.Brush` within EventID 7053 from the 'Windows Server Update Services' provider.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
2043
Where emabeded URL contain googlecontent
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Declan Byrne@dbyrne2025
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Irish Threat Hunters & Detection Engineers
1 year ago
50144
Detects the modification of VPN SSL Settings (for example, the modification of authentication rules).
This behavior was observed in pair with the addition of a VPN SSL Web Portal.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0040
Detects when a user in OneLogin assumes the identity of another user account. This could indicate an attacker using compromised credentials to impersonate another user or an insider abusing privileges.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0025
This query identifies user sign-ins leveraging legacy authentication protocols in Azure Active Directory (AAD). Legacy authentication methods, such as IMAP, POP3, Exchange ActiveSync, SMTP, and older Outlook protocols, do not support modern security features like multi-factor authentication (MFA). Their use increases the risk of account compromise, brute force attacks, and credential theft.

Monitoring for legacy authentication activity is a critical security control to detect potential unauthorized access or accounts bypassing modern security protections.
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Marvens Decayette@IronBranded
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Detections.ai Community
1 year ago
250293
Detects the execution of a script file (e.g., VBS, JS, BAT, PS1) from a removable drive using a common script interpreter. This technique is used by the threat actor Tangerine Turkey for initial access.
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Tim Peck@timpeck
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Detections.ai Community
1 year ago
2082
Detects potential exploitation of Motex LANSCOPE Endpoint Manager (CVE-2025-61932). This rule identifies when a process listening on TCP port 443 receives an inbound connection and subsequently spawns a suspicious child process (like cmd.exe or powershell.exe), a behavior consistent with exploiting a remote service vulnerability.
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Tim Peck@timpeck
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Detections.ai Community
1 year ago
1152
This rule detects a highly suspicious sequence of events: a user clicking on a URL (potentially a phishing link) followed by a risky sign-in attempt to Azure AD from an IP address outside the organization's defined range. The rule specifically looks for sign-ins with a high-risk level (>= 50) that occur after a URL click event, suggesting a potential compromise initiated by a phishing attack.
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Benjamin Zulliger@benscha
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Detections.ai Community
1 year ago
432688
https://www.proofpoint.com/us/blog/threat-insight/beyond-credentials-weaponizing-oauth-applications-persistent-cloud-access
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Steven Lim@KQLWizard
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SlimKQL
1 year ago
14672,091
Detects Airstalk malware, which exists in both PowerShell and .NET variants. The rule identifies specific strings related to its C2 communication over the AirWatch MDM API, tasking, and other unique artifacts.
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Matt Brady@mbrady5299
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Detections.ai Community
1 year ago
2042
Detects inbound emails with a Virtual Hard Disk (VHDX) file attachment. This technique has been used by APT-C-60 to deliver the SpyGlace backdoor, often disguised as a job application.
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Tim Peck@timpeck
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Detections.ai Community
1 year ago
1074
Detects a single Gmail sender address using multiple distinct display names within a short timeframe (1 hour). This behavior can indicate an attempt at impersonation, phishing, or spam campaigns where an attacker tries to appear as different entities from the same compromised or controlled email account.
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Benjamin Zulliger@benscha
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Detections.ai Community
1 year ago
184600
Detected endpoints that processed an SVG file and subsequently connected to a known malicious domain.
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Enzo Bomfim@Enzima45
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Detections.ai Community
1 year ago
20251
Detects potential exploitation of the TARmageddon vulnerability (CVE-2025-62518) by identifying multiple writes to sensitive configuration files by the same process in a short time frame. This behavior can indicate a file overwrite attack where a malicious TAR archive smuggles and extracts a secondary file to hijack build processes or application configurations.
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Tim Peck@timpeck
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Detections.ai Community
1 year ago
0093
Detects potential ASP.NET ViewState deserialization attacks, which can occur when an attacker exploits a publicly known machine key. This is often indicated by a POST request to an ASP.NET page containing a large __VIEWSTATE parameter, followed by a 500 Internal Server Error.
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Tim Peck@timpeck
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Detections.ai Community
1 year ago
50130
Detects URLs that use the `https://user@host` syntax where the 'user' part is crafted to look like a legitimate domain (e.g., `https://example.com@malicious-site.net`). This is a technique used by the Jingle Thief group (also tracked as Atlas Lion and STORM-0539) to craft convincing phishing links.
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Duo Tech@duotech
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Detections.ai Community
1 year ago
60187
Detects potential exploitation attempts of Citrix NetScaler vulnerability CVE-2025-5777 (CitrixBleed 2). This involves malformed or unusually large HTTP POST requests to the /p/u/doAuthentication.do endpoint, a technique used by groups like Earth Estries.
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Tim Peck@timpeck
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Detections.ai Community
1 year ago
50174
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