Detections

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

3,141 detections

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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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.
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Arnold Chan@slaz
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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.
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Arnold Chan@slaz
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Midnight Slayer
2 months ago
001
This rule correlates Microsoft Entra ID (formerly Azure AD) identity risk events with sign-in activity and behavioral analytics for a specific user to facilitate forensic investigation of potential identity compromise. It aggregates risk events, anomalous sign-in attempts (including failures or failed conditional access), and suspicious behavioral telemetry from the same source IP addresses associated with identified user risk.
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Shadows VMB@Vemorian_Mort
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Detections.ai Community
2 months ago
15019
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
Bharat Cyber Guardians
2 months ago
502
This rule correlates Microsoft Entra ID (formerly Azure AD) risk events identified as 'passwordSpray' with subsequent sign-in logs from the same source IP address within a 60-minute window. This helps identify successful or suspicious authentication activity originating from an IP address previously flagged for password spraying attempts against a specific user account.
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Shadows VMB@Vemorian_Mort
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Detections.ai Community
2 months ago
25282
This rule monitors for a multi-stage attack pattern involving two potential indicators: first, it identifies phishing emails containing a 'Google Docs' link combined with an attachment named 'API Logic Flaw'. Second, it detects browser activity involving the paste of JavaScript code or suspicious browser clipboard activity, which may indicate an attacker attempting to execute malicious scripts directly in the user's browser context.
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Ankit Mehta@Secvyn
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Detections.ai Community
2 months ago
000
Detects high-risk account modifications, such as adding MFA methods or OAuth consent grants, occurring shortly after a user sign-in. This pattern is indicative of post-AiTM session theft (e.g., NovaCookies) where an adversary uses a stolen session token to modify account settings for persistence or MFA bypass.
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Arnold Chan@slaz
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Detections.ai Community
2 months ago
3019
Detects non-interactive sign-ins, such as those using refresh or session tokens, originating from an IP address, ASN, device, or country that does not match the user's recent interactive sign-in history. The absence of an MFA challenge for these new contexts is characteristic of session token replay attacks, often associated with AiTM phishing campaigns.
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Ankit Mehta@Secvyn
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Detections.ai Community
2 months ago
102
Detects a high volume of outbound emails (more than 20 within a one-hour window) from a single sender containing the subject line 'Payment Transaction Failed Reminder', which is a common pattern for phishing or social engineering campaigns.
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Arnold Chan@slaz
Defender - KQL
2 months ago
001
Detects a high volume of outbound emails (more than 20 within a one-hour window) from a single sender containing the subject line 'Payment Transaction Failed Reminder', which is a common pattern for phishing or social engineering campaigns.
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Arnold Chan@slaz
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Detection & Hunting Community
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
Defender - KQL
2 months ago
000
Detects a sequence of events starting with a device code OAuth sign-in, followed within two hours by the creation or modification of inbox rules and high-frequency enumeration of email items (contacts, folders, messages, threads, people) via Microsoft Graph API. This behavior is indicative of post-compromise activity where an adversary uses OAuth device code grants to maintain access and subsequently automates inbox analysis or data harvesting.
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Arnold Chan@slaz
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Detections.ai Community
2 months ago
3015
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
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SlimKQL
2 months ago
000
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
Bharat Cyber Guardians
2 months ago
000
Detects messages sent, chats created, or members added within Microsoft Teams that involve external participants and contain embedded HTTP or HTTPS links. This behavior is indicative of potential external spearphishing or malicious link distribution through collaborative chat platforms.
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Emiliano Mema@Nosalva
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Detections.ai Community
2 months ago
19027
Detects a suspicious sequence of interactive sign-ins to Microsoft management and profile-related applications from unmanaged devices occurring within a tight 15-minute window. This behavior is indicative of post-compromise activity, potentially associated with activity clusters such as UNC6671, where an attacker interacts with account settings shortly after compromising a session.
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Arnold Chan@slaz
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Detections.ai Community
2 months ago
000
Detects a suspicious sequence of events where a user's password is changed or reset by an administrator (or help-desk role) followed within a short time window by that same user registering a new MFA device, potentially indicating a vishing-based account takeover attack (e.g., PREY-0058/UNC6671).
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Arnold Chan@slaz
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Detection & Hunting Community
2 months ago
000
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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Detections.ai Community
2 months ago
000
Detects anomalous access to Microsoft 365 services (OneDrive, SharePoint, Mail) where the user activity is characterized by a high volume of operations (more than 30) across a diverse set of objects (more than 15) within a one-hour window. The detection focuses on activity originating from specific common automation/scripting User-Agents (Microsoft Graph, Python httpx/requests) that deviate from typical, focused service account behavior.
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Arnold Chan@slaz
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Detection & Hunting Community
2 months ago
000
Detects successful Azure AD sign-ins where the user agent identifies as a Python requests library version (2.33.1 or 2.34.2) that has not been observed for that specific user account in the preceding 14 days. This behavior is indicative of anomalous automated or scripted access.
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Arnold Chan@slaz
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Detections.ai Community
2 months ago
000
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