Detections

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

837 detections

This rule detects potential phishing activity by correlating email delivery events and URL click events against a set of known malicious domains and suspicious URL paths. It identifies when a user receives an email containing a suspicious link or interacts with such a link, providing visibility into potential credential harvesting or malware delivery attempts.
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Ankit Mehta@Secvyn
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Detections.ai Community
2 months ago
204
Detects Direct Send spearphishing impersonating internal roles (IT/Finance/Procurement) with business-themed lures targeting leadership/finance titles. Rewritten: removed a non-functional sender/recipient substring check and a broken EmailPostDeliveryEvents join that made the rule rarely fire; anchored detection to the actual Direct Send signature (null envelope + domain match) and a direct IdentityInfo join; standardized auth-failure parsing to match the other rules in this set.
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Arnold Chan@slaz
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Detection & Hunting Community
2 months ago
003
Detects Direct Send spearphishing impersonating internal roles (IT/Finance/Procurement) with business-themed lures targeting leadership/finance titles. Rewritten: removed a non-functional sender/recipient substring check and a broken EmailPostDeliveryEvents join that made the rule rarely fire; anchored detection to the actual Direct Send signature (null envelope + domain match) and a direct IdentityInfo join; standardized auth-failure parsing to match the other rules in this set.
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Arnold Chan@slaz
Defender - KQL
2 months ago
003
Detects Direct Send spearphishing impersonating internal roles (IT/Finance/Procurement) with business-themed lures targeting leadership/finance titles. Rewritten: removed a non-functional sender/recipient substring check and a broken EmailPostDeliveryEvents join that made the rule rarely fire; anchored detection to the actual Direct Send signature (null envelope + domain match) and a direct IdentityInfo join; standardized auth-failure parsing to match the other rules in this set.
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Arnold Chan@slaz
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Detections.ai Community
2 months ago
103
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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Hunters
2 months ago
001
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
Bharat Cyber Guardians
2 months ago
101
Detects Direct Send spearphishing impersonating internal roles (IT/Finance/Procurement) with business-themed lures targeting leadership/finance titles. Rewritten: removed a non-functional sender/recipient substring check and a broken EmailPostDeliveryEvents join that made the rule rarely fire; anchored detection to the actual Direct Send signature (null envelope + domain match) and a direct IdentityInfo join; standardized auth-failure parsing to match the other rules in this set.
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Arnold Chan@slaz
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Detections.ai Community
2 months ago
303
Detects the RejectDirectSend bypass (null SMTP envelope sender + internal-domain spoof). Tightened to require Microsoft's composite auth verdict OR all of SPF/DKIM/DMARC failing (vs. any one), excludes known-approved Direct Send relay IPs, and excludes likely-legitimate bulk/newsletter traffic via BulkComplaintLevel.
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Arnold Chan@slaz
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Detection & Hunting Community
2 months ago
003
Detects inbound emails that use a combination of finance-related keyword patterns in the domain and ActiveCampaign-specific relay infrastructure naming conventions. This technique is often used in phishing campaigns to bypass filters by leveraging trusted third-party email service provider infrastructure.
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Ankit Mehta@Secvyn
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Detections.ai Community
2 months ago
103
This rule detects a correlation between an email phishing burst (high volume of emails with a specific failed payment subject) and the subsequent creation of suspicious 'x_trace_' files in 'var/report/' directories. This pattern is indicative of a phishing campaign where a malicious attachment or link might be attempting to write local tracking or diagnostic files on a victim's host.
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Ankit Mehta@Secvyn
Defender - KQL
2 months ago
001
Detects high-volume phishing emails that utilize subjects claiming extreme discounts (e.g., 65% off) and contain links to domains ending in the .shop top-level domain (TLD). The rule correlates email subjects with URL domains and alerts when multiple recipients are targeted by the same sender/domain combination.
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Arnold Chan@slaz
Defender - KQL
2 months ago
000
Detects inbound emails masquerading as reputable advisory firms (PwC or KPMG) using lookalike sender domains, combined with wire-transfer fraud phrases in the subject line. Correlates with identity logon telemetry for the same fraudulent WhatsApp Business phone number, enabling detection across both email and authentication channels. Note: message body content is not available in the EmailEvents schema, so fraud-phrase matching is subject-only.
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Arnold Chan@slaz
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Midnight Slayer
2 months ago
000
Detects inbound emails masquerading as reputable advisory firms (PwC or KPMG) using lookalike sender domains, combined with wire-transfer fraud phrases in the subject line. Correlates with identity logon telemetry for the same fraudulent WhatsApp Business phone number, enabling detection across both email and authentication channels. Note: message body content is not available in the EmailEvents schema, so fraud-phrase matching is subject-only.
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Arnold Chan@slaz
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Detection & Hunting Community
2 months ago
000
This rule monitors for inbound external emails where the sender requests private communication (e.g., 'private email' or 'personal address') in combination with keywords related to sensitive business topics like M&A, legal, or urgent financial transactions. This pattern is characteristic of Business Email Compromise (BEC) or social engineering attempts designed to move sensitive conversations outside of monitored corporate channels.
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Arnold Chan@slaz
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Detections.ai Community
2 months ago
000
Detects potential Business Email Compromise (BEC) related to 'Phantom Deal' fraud. The rule identifies email threads where a user receives an urgent request for proof of payment (MT103/UETR) within 72 hours of an email discussion involving both wire transfer/payment keywords and M&A/deal context.
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Arnold Chan@slaz
Defender - KQL
2 months ago
000
Detects potential Business Email Compromise (BEC) related to 'Phantom Deal' fraud. The rule identifies email threads where a user receives an urgent request for proof of payment (MT103/UETR) within 72 hours of an email discussion involving both wire transfer/payment keywords and M&A/deal context.
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Arnold Chan@slaz
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Detections.ai Community
2 months ago
000
Detects inbound emails containing keywords associated with known ransomware extortion tactics (e.g., mention of specific ransomware names, data leaks, and payment demands). The rule filters for inbound traffic to identify external threats while excluding potential internal-generated traffic.
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Arnold Chan@slaz
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Midnight Slayer
2 months ago
001
Detects anomalous email access patterns across multiple mailboxes using specific application identifiers or access contexts often associated with automated collection tools. This rule flags when an application accesses more than 20 items across distinct mailboxes in a 15-minute window, which is indicative of potential unauthorized bulk email collection or data exfiltration.
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Arnold Chan@slaz
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Midnight Slayer
2 months ago
101
This rule detects potential phishing activity by correlating email delivery events and URL click events against a set of known malicious domains and suspicious URL paths. It identifies when a user receives an email containing a suspicious link or interacts with such a link, providing visibility into potential credential harvesting or malware delivery attempts.
avatar
Ankit Mehta@Secvyn
Bharat Cyber Guardians
2 months ago
103
Detects the RejectDirectSend bypass (null SMTP envelope sender + internal-domain spoof). Tightened to require Microsoft's composite auth verdict OR all of SPF/DKIM/DMARC failing (vs. any one), excludes known-approved Direct Send relay IPs, and excludes likely-legitimate bulk/newsletter traffic via BulkComplaintLevel.
avatar
Arnold Chan@slaz
avatar
Midnight Slayer
2 months ago
001
Detects Direct Send spearphishing impersonating internal roles (IT/Finance/Procurement) with business-themed lures targeting leadership/finance titles. Rewritten: removed a non-functional sender/recipient substring check and a broken EmailPostDeliveryEvents join that made the rule rarely fire; anchored detection to the actual Direct Send signature (null envelope + domain match) and a direct IdentityInfo join; standardized auth-failure parsing to match the other rules in this set.
avatar
Arnold Chan@slaz
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Midnight Slayer
2 months ago
001
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