Detections

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

837 detections

Detects suspicious O365 'MailItemsAccessed' activity using a specific OAuth application (AppId c999ed3e-27ae-4cb3-b3a2-46b056af63d3) and ClientId (5d661950-3475-41cd-a2c3-d671a3162bc1) with an 'Bind' operation type. This pattern is often associated with unauthorized email access across multiple tenant accounts. The rule triggers when at least 5 events are detected across 2 or more distinct tenant accounts within a 1-minute window, using a specific Firefox user agent.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
001
Detects the creation or modification of O365 inbox rules designed to move incoming emails to the 'Deleted Items' folder, delete messages, or mark them as read. This behavior is a common indicator of an adversary attempting to hide phishing lures, security alerts, or C2 communications within a compromised mailbox.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
001
This rule detects high-confidence phishing emails that were delivered to either the Inbox or Junk folder. It explicitly filters out messages that have been explicitly allowed by organization-level policies, user-level actions, or specific safe-sender bypass mechanisms, ensuring the alert focuses on malicious emails that bypassed standard security filters without an authorized exception.
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Arnold Chan@slaz
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Detection & Hunting Community
1 month ago
001
Detects the creation of an email inbox rule that includes both a concealment/deletion action and an external forwarding destination, occurring within 4 hours of a high-risk or compromised device-code authentication event. This pattern is indicative of account takeover where an attacker establishes persistence and exfiltration while hiding their activity.
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Arnold Chan@slaz
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Detection & Hunting Community
1 month ago
001
Detects the creation of an email inbox rule that includes both a concealment/deletion action and an external forwarding destination, occurring within 4 hours of a high-risk or compromised device-code authentication event. This pattern is indicative of account takeover where an attacker establishes persistence and exfiltration while hiding their activity.
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Arnold Chan@slaz
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Midnight Slayer
1 month ago
001
Detects the creation of an email inbox rule that includes both a concealment/deletion action and an external forwarding destination, occurring within 4 hours of a high-risk or compromised device-code authentication event. This pattern is indicative of account takeover where an attacker establishes persistence and exfiltration while hiding their activity.
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Arnold Chan@slaz
Defender - KQL
1 month ago
001
This rule detects potentially unauthorized access or downloading of files from SharePoint and OneDrive, as well as specific MailItemsAccessed events associated with known exfiltration toolkit patterns within Microsoft 365. It flags individual events matching these criteria as a baseline for identifying suspicious data access behaviors.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
002
Detects anomalous, high-volume access to email items by specific applications known to be associated with suspicious activity or unusual access patterns within the Exchange environment, potentially indicating email harvesting or data exfiltration.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
002
This rule detects when a user grants OAuth application permissions for high-risk scopes (e.g., Mail, Files) to an application that was registered within the last 7 days. It correlates this event with subsequent suspicious actions performed by the same user, specifically mailbox rule modifications or file download activity, which are common indicators of post-compromise activity following OAuth consent phishing.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
000
This rule detects mass phishing campaigns by identifying HTML/HTM email attachments that contain embedded URLs. It monitors for a pattern where the same sender distributes these attachments to multiple recipients, a common behavior for HTML smuggling delivery vectors where malicious payloads are constructed client-side to bypass static email gateway inspection.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
000
Detects incoming EXTERNAL emails containing subject lines indicative of meeting invitations or call records, which include external URLs pointing to non-standard or unverified cloud storage providers, combined with explicit remote-access/support solicitation language. Requiring the remote-access/support signal and excluding internal-to-internal mail narrows this to callback-phishing style lures rather than routine meeting correspondence.
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Arnold Chan@slaz
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Detection & Hunting Community
1 month ago
609
Detects indicators associated with the exploitation of CVE-2025-3248 in Langflow. The rule identifies anomalous web requests targeting the /api/v1/validate/code endpoint, subsequent suspicious process creation (base64 encoded payloads in Python/shell), and network communication with identified command and control (C2) or data exfiltration IP addresses. It also includes alerts for observed contact with known extortion email addresses.
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Ankit Mehta@Secvyn
Defender - KQL
1 month ago
104
This rule detects a suspicious monetization pattern where a user account experiences a high-risk sign-in event, followed shortly (within 2 hours) by the creation or modification of inbox rules. This pattern is often indicative of account compromise, where an adversary configures mailbox rules (e.g., forwarding or redirection) to facilitate data exfiltration or financial fraud.
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Arnold Chan@slaz
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Detection & Hunting Community
1 month ago
000
This rule detects a suspicious monetization pattern where a user account experiences a high-risk sign-in event, followed shortly (within 2 hours) by the creation or modification of inbox rules. This pattern is often indicative of account compromise, where an adversary configures mailbox rules (e.g., forwarding or redirection) to facilitate data exfiltration or financial fraud.
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Arnold Chan@slaz
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Midnight Slayer
1 month ago
000
This rule detects a suspicious monetization pattern where a user account experiences a high-risk sign-in event, followed shortly (within 2 hours) by the creation or modification of inbox rules. This pattern is often indicative of account compromise, where an adversary configures mailbox rules (e.g., forwarding or redirection) to facilitate data exfiltration or financial fraud.
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Arnold Chan@slaz
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Hunters
1 month ago
000
Detects the creation or modification of email inbox rules that perform suspicious actions such as deleting, moving to folders, or forwarding emails, specifically when those rules target keywords associated with sensitive financial or business communications like invoices, payments, or wire transfers. This behavior is indicative of an attacker attempting to hide evidence of a compromise or intercept sensitive business communications.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
003
This rule detects network and email activity associated with a list of known suspicious or 'ghost' domains. It monitors email sender and recipient addresses, email URL links, and DNS query logs for matches against the predefined domain list, identifying potential spearphishing or command-and-control communication.
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Ankit Mehta@Secvyn
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SlimKQL
1 month ago
206
Detects incoming emails processed by Rspamd that exhibit suspicious authentication header signatures. The rule identifies emails lacking DKIM, ARC, or user agent information while simultaneously showing a zero receive count, potentially indicating spoofed, unauthenticated, or malformed phishing attempts.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
001
This rule detects inbound phishing emails that leverage urgent security themes (e.g., passkey, SSO, or MFA updates) to lure users into clicking links. It correlates these emails with subsequent URL clicks and suspicious sign-in activity, such as MFA failures, which are indicative of an attempt to compromise credentials or bypass MFA.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
304
Detects emails from specific suspicious domains or senders masquerading as executive roles (CEO, CFO) that contain attachments with 'invoice' in the filename and subject lines indicative of urgent financial transactions (e.g., payment, wire transfer). This pattern is commonly associated with Business Email Compromise (BEC) and malicious document delivery.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
406
Detects incoming emails from specific suspicious domains that pass authentication checks (SPF, DKIM, DMARC) but contain subject lines commonly associated with phishing campaigns, such as invoices, payment requests, or urgent notifications. The rule includes associated URL and attachment information for further analysis.
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Ankit Mehta@Secvyn
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SlimKQL
1 month ago
207
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