Detections
Explore public detection logic contributed by the community across SIEM and rule languages.
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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.
Detects incoming emails where the SMTP envelope sender (MAIL FROM) is blank, but the visible 'From' header displays an internal/accepted domain. This technique is often used to bypass email authentication filters. The rule specifically alerts on cases where SPF, DKIM, or DMARC checks failed or returned 'none', yet the message was still delivered to an inbox or folder, suggesting a configuration gap or allow-list override.
This rule monitors for inbound email activity containing sender domains or embedded URL domains known to be associated with malicious phishing campaigns. It flags emails matching a predefined list of suspicious sender domains or URLs that resolve to known malicious infrastructure.
Detects Direct Send bypass (null envelope + internal-domain spoof) using a file/document-sharing lure aimed at leadership. Tightened: added inbound-direction and auth-failure requirements (was previously missing any authentication check, so legitimate SharePoint/OneDrive-style sharing notifications from real internal senders could have matched), delivered-only filter, and case-insensitive recipient/job-title join.
Detects SCL-9 (high-confidence phishing/spam) messages that still reach an inbox, indicating an allow-list or transport-rule override, and enriches with any recent tenant mail-flow admin changes. Rewritten: removed a no-op self-join on EmailEvents and a broken exact-match join against CloudAppEvents' raw audit blob (was comparing a sender address against a whole JSON record and would never match); now excludes messages later auto-remediated (e.g. ZAP-quarantined) via the native LatestDeliveryLocation field, and correlates admin rule/allow-list changes via substring match over a cross join.
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.
This rule detects network connections or DNS queries to known phishing domains (typosquatted Microsoft login domains), DeadDrop Resolver domains, and suspicious HTML payloads served from common CDN/package hosting sites (e.g., unpkg.com, npmmirror.com, cdn.jsdelivr.net, yarnpkg.com). These patterns are indicative of initial access attempts via phishing or the secondary stage of malware C2 communication.
This rule monitors email traffic for communication involving identified malicious domains and sender addresses. It cross-references sender information in the EmailEvents log with a predefined set of suspicious domains and email addresses, highlighting potential phishing or malicious outreach attempts.
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.
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.
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.
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.
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.
Detects Direct Send bypass (null envelope + internal-domain spoof) using a file/document-sharing lure aimed at leadership. Tightened: added inbound-direction and auth-failure requirements (was previously missing any authentication check, so legitimate SharePoint/OneDrive-style sharing notifications from real internal senders could have matched), delivered-only filter, and case-insensitive recipient/job-title join.
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.
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.
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.
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.
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.
Detects forged Citibank payment confirmation/account statement PDFs used in Phantom Deal BPC fraud to falsely demonstrate wire transfer progress; requires combination of bank branding with fraud-specific SWIFT/routing/CTA artifacts
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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