Detections

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

3,141 detections

This rule identifies phishing attempts by detecting inbound emails where the sender's domain or any embedded URLs within the email content match a pre-defined list of known malicious domains. It flags emails for further investigation by correlating sender domain data and URL information found in the email communication.
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Ankit Mehta@Secvyn
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Detections.ai Community
2 months ago
13010
This rule detects potential spearphishing activity by correlating email attachments containing specific 'Request for Quotation' filenames with subsequent suspicious file creation events on endpoints. It specifically looks for matching attachments (MSG or PDF) from email logs and tracks if similar file patterns appear in Microsoft Outlook content or temporary folders on host devices.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
2 months ago
003
This rule detects potential spearphishing activity by correlating email attachments containing specific 'Request for Quotation' filenames with subsequent suspicious file creation events on endpoints. It specifically looks for matching attachments (MSG or PDF) from email logs and tracks if similar file patterns appear in Microsoft Outlook content or temporary folders on host devices.
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Ankit Mehta@Secvyn
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Detections.ai Community
2 months ago
203
Detects anomalous sign-in behavior shortly after a successful MFA-authenticated session in Microsoft 365. This rule flags scenarios where a subsequent session for the same user occurs within a short window (30 minutes) from a different IP, ASN, User-Agent, or device identifier, potentially indicating the replay of a stolen session cookie obtained via Adversary-in-the-Middle (AiTM) phishing.
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Arnold Chan@slaz
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Midnight Slayer
2 months ago
303
Detects incoming emails that impersonate DocuSign notifications, specifically looking for typical phishing lures involving 'Remittance Advice' and a call-to-action to 'Tap here to view document'. This rule identifies emails using common social engineering tactics to harvest credentials or distribute malware via fake document links.
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Arnold Chan@slaz
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Midnight Slayer
2 months ago
003
This rule identifies suspicious emails containing password-protected attachments or files often used to bypass email security gateways. It monitors for emails where the subject line includes password hints or keywords like 'protected' or 'secure', combined with the presence of attachments and URL-based links, which are common tactics in phishing campaigns to distribute malicious payloads.
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Arnold Chan@slaz
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Midnight Slayer
2 months ago
003
This rule detects potential phishing activity by identifying bulk email campaigns (5 or more recipients) where either the email subject contains known suspicious keywords (e.g., 'password', 'urgent', 'invoice') or the Reply-To address domain differs from the sender domain. The rule specifically excludes emails with attachments or URLs, focusing on social engineering pretexts that aim to initiate a conversation or gather information without external payloads.
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Arnold Chan@slaz
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Midnight Slayer
2 months ago
003
Audits Direct Send traffic against an approved-IP watchlist, flagging unauthenticated inbound mail spoofing an internal domain from an unrecognized source IP. Fixed: RecipientDomain/SenderFromDomain were referenced but never defined (would have errored at runtime); replaced with derived SenderDomain/RecipientDomain consistent with the sibling rules. Removed a noisy display-name-contains-domain OR-branch. Replaced an always-true-in-practice auth check (required every one of SPF/DKIM/DMARC to show literal "Pass", which fails for many legitimate senders that pass via alignment on only one protocol) with the same CompAuth/all-three-fail logic used elsewhere in this set.
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Arnold Chan@slaz
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Midnight Slayer
2 months ago
003
This rule monitors Office 365 SharePoint file operations and search queries for patterns indicative of automated discovery and exfiltration of sensitive content. It specifically identifies high-frequency search queries involving wildcard parameters used in SharePoint content indexing, which may suggest an adversary is systematically crawling or enumerating organizational documents.
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Ankit Mehta@Secvyn
Defender - KQL
2 months ago
001
Detects cloud application events originating from suspicious or specific User-Agent strings, including 'python-requests' and identified outdated or potentially spoofed Chrome versions (146, 150, 151.0.0). This behavior often correlates with automated scripts or bot activity interacting with cloud services.
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Ankit Mehta@Secvyn
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Detection & Hunting Community
2 months ago
201
Detects cloud application events originating from suspicious or specific User-Agent strings, including 'python-requests' and identified outdated or potentially spoofed Chrome versions (146, 150, 151.0.0). This behavior often correlates with automated scripts or bot activity interacting with cloud services.
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Ankit Mehta@Secvyn
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SlimKQL
2 months ago
001
Detects a user performing a high volume of SharePoint site discovery queries within a one-hour window. This behavior often indicates an adversary attempting to map site structures and discover content across an organization's SharePoint environment.
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Ankit Mehta@Secvyn
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SlimKQL
2 months ago
001
Detects cloud application events originating from suspicious or specific User-Agent strings, including 'python-requests' and identified outdated or potentially spoofed Chrome versions (146, 150, 151.0.0). This behavior often correlates with automated scripts or bot activity interacting with cloud services.
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Ankit Mehta@Secvyn
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Detections.ai Community
2 months ago
101
Detects anomalous, high-volume access to email items or attachments in Microsoft Exchange Online by a single account from a single IP address, which may indicate account compromise, unauthorized mail harvesting, or data exfiltration.
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Ankit Mehta@Secvyn
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Detections.ai Community
2 months ago
101
Detects anomalous user behavior where a file search query is followed by a high volume of file downloads within a short period (30 minutes) from the same IP address. This behavior is indicative of an attacker searching for sensitive documents and performing bulk extraction or exfiltration.
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Ankit Mehta@Secvyn
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Detections.ai Community
2 months ago
001
Detects interaction with known infrastructure associated with the PREY-0058 campaign, which utilizes Adversary-in-the-Middle (AiTM) phishing lures mimicking passkey or MFA registration pages to target Microsoft 365 and other SaaS applications.
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Ankit Mehta@Secvyn
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Detection & Hunting Community
2 months ago
001
Detects inbound emails associated with the Mirage phishing campaign. The detection monitors for known malicious domains in sender information and URL links, as well as specific command-and-control (C2) IP addresses and URL patterns.
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Ankit Mehta@Secvyn
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SlimKQL
2 months ago
203
Detects inbound emails associated with the Mirage phishing campaign. The detection monitors for known malicious domains in sender information and URL links, as well as specific command-and-control (C2) IP addresses and URL patterns.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
2 months ago
705
This rule detects modifications to Group Policy Objects (GPO) or Microsoft Entra (formerly Azure AD) policies that weaken established security controls. For GPO, it monitors Event ID 5136 for changes to security-relevant attributes (e.g., disabling firewall or real-time monitoring) in Active Directory. For Entra, it monitors audit logs for administrative operations that reduce security posture, such as disabling MFA, lowering authentication trust, or deleting Conditional Access policies. It includes filters to exclude legitimate, documented change management activities.
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Arnold Chan@slaz
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Midnight Slayer
2 months ago
002
This rule detects modifications to Group Policy Objects (GPO) or Microsoft Entra (formerly Azure AD) policies that weaken established security controls. For GPO, it monitors Event ID 5136 for changes to security-relevant attributes (e.g., disabling firewall or real-time monitoring) in Active Directory. For Entra, it monitors audit logs for administrative operations that reduce security posture, such as disabling MFA, lowering authentication trust, or deleting Conditional Access policies. It includes filters to exclude legitimate, documented change management activities.
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Arnold Chan@slaz
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Detections.ai Community
2 months ago
002
Detects the delivery of .mobileconfig files or related configuration profile types (e.g., .plist, .xml) via email. These profiles are used on macOS and iOS devices to modify system settings, such as mail, calendar, or contact synchronization, and can be used to install malicious root certificates to enable Man-in-the-Middle (MITM) attacks. This rule accounts for direct attachments as well as those concealed within zip archives.
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Ankit Mehta@Secvyn
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SlimKQL
2 months ago
202
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