Detections

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

2,983 detections

Detects Microsoft 365 Outlook calendar events with highly anomalous future dates (specifically the year 2050) or specific subject patterns, which are indicative of a command-and-control (C2) communication channel established via calendar item properties.
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Duo Tech@duotech
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Detections.ai Community
3 months ago
405
Detects Microsoft 365 Outlook calendar events being updated via Graph API where the subject is changed to a suspicious C2-like string (e.g., 'Boss Report ID:' or 'Boss update ID:'). This behavior is consistent with attackers using Outlook calendar events as a covert communication channel or for command and control signaling.
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Duo Tech@duotech
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Detections.ai Community
3 months ago
405
Detects Microsoft Graph API requests targeting user mailboxes within a tenant or organization structure likely associated with Israeli legal entities, identified by .co.il domain patterns in the Request URI.
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Duo Tech@duotech
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Detections.ai Community
3 months ago
004
Detects suspicious modifications or deletions of Outlook calendar events using the Microsoft Graph API, potentially indicating the use of calendar infrastructure as a command-and-control (C2) heartbeat or exfiltration channel. The rule monitors for specific pattern-based event updates or deletions following calendar enumeration, which is a technique used to maintain persistent communication or exfiltrate small amounts of data.
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Duo Tech@duotech
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Detections.ai Community
3 months ago
104
Detects Microsoft 365 Outlook calendar events being updated via Graph API where the subject is changed to a suspicious C2-like string (e.g., 'Boss Report ID:' or 'Boss update ID:'). This behavior is consistent with attackers using Outlook calendar events as a covert communication channel or for command and control signaling.
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Duo Tech@duotech
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Detections.ai Community
3 months ago
704
Detects potential username enumeration attempts against Microsoft Entra ID (Azure AD) by monitoring for the 'AADSTS50034' error code, which occurs when a sign-in attempt is made with a username that does not exist in the directory. This behavior is often associated with adversary reconnaissance to identify valid user accounts.
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Duo Tech@duotech
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Detections.ai Community
4 months ago
12025
Detects unauthorized modifications to the 'wp_users' table in a WordPress database. The rule correlates specific WordPress REST API calls (oEmbed or batch processing endpoints) originating from the same source IP address that performs database inserts or updates, while explicitly excluding activity originating from verified Admin UI sessions.
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Emiliano Mema@Nosalva
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Detections.ai Community
3 months ago
003
Detects high-frequency Resource Owner Password Credentials (ROPC) authentication attempts originating from a single IP address against multiple different user accounts within a 15-minute window. This behavior is indicative of a password spraying or brute force campaign targeting cloud authentication services.
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Duo Tech@duotech
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Detections.ai Community
4 months ago
18022
Detects web server request patterns associated with a 'Kali365' phishing campaign that utilizes device code authorization flows. The rule identifies suspicious JSON design payloads that simulate various enterprise brands (e.g., Microsoft 365, DocuSign, Adobe) in combination with a 'device_code' flow identifier, indicative of a credential or token-harvesting attack.
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Duo Tech@duotech
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Detections.ai Community
3 months ago
003
Detects anomalous post-authentication activity in n8n where the authentication issuer for an account changes from historical norms. This identifies potential account takeover (ATO) scenarios where a hijacked token or cross-issuer session is used to perform lateral movement, workflow manipulation, credential access, or data exfiltration, consistent with behaviors associated with vulnerabilities like CVE-2026-59208.
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Ethan Andrews@eandrews
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Federal Signal Detections
4 months ago
4011
Detects the unauthorized PyPI release of mrmustard 0.7.4 uploaded during the known malicious publish window following the maintainer account compromise.
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Duo Tech@duotech
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Detections.ai Community
3 months ago
001
Detects deletion of GitHub Actions workflow files combined with anomalous branch names/commit hashes, indicating the attacker concealing the malicious CI workflow used in this supply-chain compromise.
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Duo Tech@duotech
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Detections.ai Community
3 months ago
001
Detects unauthenticated exploitation attempts targeting WordPress sites using wp2shell techniques. The rule identifies malicious payloads attempting to leverage RSS, Navigation, or Calendar Gutenberg blocks in conjunction with the batch REST API to achieve Remote Code Execution.
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Duo Tech@duotech
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Detections.ai Community
3 months ago
001
Detects unauthenticated exploitation attempts targeting WordPress sites using wp2shell techniques. The rule identifies malicious payloads attempting to leverage RSS, Navigation, or Calendar Gutenberg blocks in conjunction with the batch REST API to achieve Remote Code Execution.
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Duo Tech@duotech
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Detections.ai Community
3 months ago
001
This rule detects potential OAuth Device Code Flow phishing attacks where users are directed to malicious lure pages on romnor[.]ca to enter a Microsoft device code. It also alerts on authentication activity associated with a specific malicious OAuth client ID (d3590ed6-52b3-4102-aeff-aad2292ab01c) known to be used by a phishing backend to poll and claim OAuth tokens.
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Tim Peck@timpeck
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SecOps Signals
4 months ago
1020
Detects anomalous activity in Microsoft 365 calendar events where potential C2 data is exfiltrated or synchronized. This is identified by the creation or modification of calendar events containing suspicious file names (e.g., File0.txt, File1.txt) or specific command-and-control markers within the event subject.
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Duo Tech@duotech
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Detections.ai Community
3 months ago
102
Detects anomalous access to Outlook calendar attachments via the Microsoft Graph API, specifically targeting a file named 'file0.txt'. This activity may indicate a technique where attackers use calendar events as a covert channel for data exfiltration or delivery of malicious payloads.
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Duo Tech@duotech
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Detections.ai Community
3 months ago
002
Detects Microsoft 365 Outlook calendar events with highly anomalous future dates (specifically the year 2050) or specific subject patterns, which are indicative of a command-and-control (C2) communication channel established via calendar item properties.
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Duo Tech@duotech
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Detections.ai Community
3 months ago
202
This rule identifies suspicious email messages that contain isolated blocks of text preceded by at least two whitespace characters (including newlines, carriage returns, or tabs). This pattern is often used by threat actors to obfuscate content, attempt to bypass email gateway filters, or hide malicious strings from security scanners by breaking up content flow.
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Duo Tech@duotech
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Detections.ai Community
4 months ago
2011
Detects anomalous, automated data exfiltration cycles in Microsoft 365 environments consistent with the Helix threat group. The rule identifies a pattern of successful sign-ins followed within 6 hours by new MFA registration, suspicious SharePoint enumeration, and a high-frequency, non-human-paced burst of file downloads.
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Ethan Andrews@eandrews
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Federal Signal Detections
4 months ago
54049
Detects sign-in events where a sign-in attempt is performed with a valid application ID but contains a blank application name, indicating potential spoofing of an OAuth client to bypass Conditional Access policies. The rule specifically monitors instances where Conditional Access status is recorded as 'notApplied'.
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Duo Tech@duotech
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Detections.ai Community
4 months ago
0010
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