Detections

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

3,141 detections

This rule detects incoming emails that contain common phishing lure keywords or reference ID patterns in the subject line, combined with signs of email spoofing (same sender/recipient domain) or a failure in email authentication protocols (DKIM, SPF, or DMARC).
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
2 months ago
307
Detects coordinated email phishing campaigns by normalizing email subjects to identify recurring templates and flagging those sent to a high volume of recipients across multiple organizations within a short timeframe. The rule specifically targets financial and urgent pretexts from external senders, similar to observed techniques in impersonation campaigns.
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Arnold Chan@slaz
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Midnight Slayer
2 months ago
000
This rule detects high-volume email bursts sent through third-party bulk email providers where the sender domain exhibits SPF, DKIM, or DMARC alignment failures. This behavior is indicative of mass phishing campaigns, such as those associated with 'Operation DoppelBrand', attempting to bypass email authentication defenses using compromised or unauthorized infrastructure.
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Arnold Chan@slaz
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Detection & Hunting Community
2 months ago
000
This rule detects high-volume email bursts sent through third-party bulk email providers where the sender domain exhibits SPF, DKIM, or DMARC alignment failures. This behavior is indicative of mass phishing campaigns, such as those associated with 'Operation DoppelBrand', attempting to bypass email authentication defenses using compromised or unauthorized infrastructure.
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Arnold Chan@slaz
Defender - KQL
2 months ago
000
Detects successful post-delivery email remediation actions (such as ZAP, manual deletion, or moving to junk) performed on emails associated with the Operation DoppelBrand campaign, identified by specific sender domains (service-nowinc.com, domainlify.net) or suspicious invoice-fraud subject lines.
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Arnold Chan@slaz
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Midnight Slayer
2 months ago
000
Detects inbound emails from external domains containing keywords related to financial transactions or urgency in the subject line (specifically matching forwarded or reply formats) accompanied by PDF or HTML attachments. This heuristic approach attempts to identify potential business email compromise (BEC) or phishing lures mimicking invoices or approval requests in environments where raw email body content is unavailable.
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Arnold Chan@slaz
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Midnight Slayer
2 months ago
000
Detects inbound emails from external domains containing keywords related to financial transactions or urgency in the subject line (specifically matching forwarded or reply formats) accompanied by PDF or HTML attachments. This heuristic approach attempts to identify potential business email compromise (BEC) or phishing lures mimicking invoices or approval requests in environments where raw email body content is unavailable.
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Arnold Chan@slaz
Defender - KQL
2 months ago
000
Detects spoofed ServiceNow invoice attachments/HTML used in Operation DoppelBrand BEC campaign with attacker-controlled GO2BANK ACH details
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Arnold Chan@slaz
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Midnight Slayer
2 months ago
000
Detects spoofed ServiceNow invoice attachments/HTML used in Operation DoppelBrand BEC campaign with attacker-controlled GO2BANK ACH details
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Arnold Chan@slaz
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Detection & Hunting Community
2 months ago
000
Detects spoofed ServiceNow invoice attachments/HTML used in Operation DoppelBrand BEC campaign with attacker-controlled GO2BANK ACH details
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Arnold Chan@slaz
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Detections.ai Community
2 months ago
000
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.
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Arnold Chan@slaz
Defender - KQL
2 months ago
104
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
Defender - KQL
2 months ago
004
Detects anomalous, non-interactive sign-in activity in Microsoft 365 that suggests session cookie replay (Pass-the-Cookie). The rule correlates successful, MFA-validated interactive sign-ins against subsequent, non-interactive sign-ins that lack MFA, occur from a different device and IP address within a short time window, and bypass standard interactive re-authentication.
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Arnold Chan@slaz
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Detections.ai Community
2 months ago
001
This rule correlates email sender activity with network, cloud, and identity logs by matching traffic against a specific IP range (160.79.104.0/21) identified as malicious or suspicious. The rule flags instances where this range appears as an email sender IP or as a remote/source IP address across various infrastructure indices, potentially indicating adversary communication or exfiltration.
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Arnold Chan@slaz
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Detection & Hunting Community
2 months ago
000
This rule monitors various logs (email, entra, device, graph, cloud) for IP addresses (source or remote) that match a specific CIDR range (160.79.104.0/21). This is typically used to identify traffic originating from or communicating with infrastructure identified as malicious or suspicious by threat intelligence.
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Arnold Chan@slaz
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Midnight Slayer
2 months ago
100
This rule monitors various logs (email, entra, device, graph, cloud) for IP addresses (source or remote) that match a specific CIDR range (160.79.104.0/21). This is typically used to identify traffic originating from or communicating with infrastructure identified as malicious or suspicious by threat intelligence.
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Arnold Chan@slaz
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Hunters
2 months ago
100
This rule monitors various logs (email, entra, device, graph, cloud) for IP addresses (source or remote) that match a specific CIDR range (160.79.104.0/21). This is typically used to identify traffic originating from or communicating with infrastructure identified as malicious or suspicious by threat intelligence.
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Arnold Chan@slaz
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Detections.ai Community
2 months ago
000
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.
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Ankit Mehta@Secvyn
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Detections.ai Community
2 months ago
504
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.
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Ankit Mehta@Secvyn
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Detections.ai Community
2 months ago
104
Detects a privilege escalation technique where an attacker with application management permissions adds a credential to the 'Office 365 Exchange Online' service principal (SP). The attacker then leverages the SP's 'Domain.ReadWrite.All' permission to add or modify a federated domain, allowing them to forge tokens for any hybrid user.
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Arnold Chan@slaz
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Midnight Slayer
2 months ago
102
Detects anomalous reuse of an authenticated Microsoft 365 session cookie shortly after a successful MFA-satisfied sign-in. The detection identifies scenarios where the subsequent access originates from a different IP address, device, or user agent without an intervening MFA challenge, which is a pattern indicative of session hijacking techniques like Adversary-in-the-Middle (AiTM) or session token replay.
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Arnold Chan@slaz
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Midnight Slayer
2 months ago
002
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