Detections

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

545 detections

This rule detects attempts to purge mailbox data using Exchange Web Services (EWS) by looking for HTTP requests to '/EWS/Exchange.asmx' containing the 'HardDelete' string in the client body. This activity is indicative of an attacker attempting to remove evidence or sensitive information from a compromised mailbox.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
003
This rule detects the creation of a new inbox rule via Exchange Web Services (EWS) that could be used to hide phishing replies. Specifically, it looks for HTTP traffic to '/EWS/Exchange.asmx' with 'NewInboxRule' in the client body, indicating an attempt to create a new inbox rule.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
003
Identifies a risky sign-in to a known O365 landing page followed shortly by the creation of an inbox rule that deletes messages or moves them to junk/trash. This pattern frequently indicates account compromise (e.g., BEC or AiTM) attempting to hide malicious activity.
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Bryant Smith@flowstate
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Detections.ai Community
5 months ago
15127
This rule detects the creation of malicious Outlook rules via Exchange Web Services (EWS). It specifically looks for HTTP traffic to '/EWS/Exchange.asmx' containing the 'CreateRule' string in the client body, indicating an attempt to establish persistence within an Outlook environment.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
003
This rule detects potential email harvesting attempts via Exchange Web Services (EWS). It specifically looks for HTTP requests to the '/EWS/Exchange.asmx' endpoint containing 'FindItem' in the client body, indicating an attempt to enumerate or search for items (like emails) within mailboxes. A threshold is applied to prevent excessive alerts from legitimate, but frequent, EWS activity.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
002
This rule detects attempts to enumerate email accounts using Exchange Web Services (EWS). It specifically looks for HTTP requests to the '/EWS/Exchange.asmx' URI containing the 'FindItem' content in the client body. A threshold of 10 such requests within 30 seconds from the same source IP triggers the alert, indicating a potential network scan or discovery activity targeting email accounts.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
002
This rule detects when a single user removes permissions from 5 or more mailboxes within a one-hour window in an Exchange environment. This activity could indicate an attempt to cover tracks or disrupt access to mailboxes by an attacker.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
5 months ago
001
This rule detects network traffic indicating the installation of a Transport Agent on an Exchange server. It specifically looks for the strings "TransportAgent" and "Install-TransportAgent" in TCP traffic directed to port 25 of the home network, suggesting a potential malicious or unauthorized installation of an Exchange Transport Agent.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
002
This rule detects the delivery of a malicious Outlook form script over HTTP. It specifically looks for HTTP traffic flowing to the client that contains the strings "IPM.Note", "Script", and "VBScript" within the file data, indicating an attempt to deliver a VBScript-based Outlook form.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
002
Detects the creation or modification of Exchange inbox rules used by Kali365 designed to suppress security alerts by moving, deleting, or marking as read emails containing specific keywords. This technique is often used by adversaries to hide their activities or prevent detection.
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Tim Peck@timpeck
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Detections.ai Community
5 months ago
9197
This rule detects when a user adds mailbox permissions to three or more mailboxes within a one-hour window in Exchange Online. This behavior can indicate an adversary attempting to gain persistent access to multiple mailboxes, often for data exfiltration or further compromise.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
5 months ago
000
Detects the creation or modification of inbox rules in Exchange, which OilRig uses to hide and manage their steganographic email C2 communications.
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Kaung Khant Ko@kaungkhantko
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Detections.ai Community
5 months ago
110237
Detects HTTP POST requests to the OWA directory containing rule or forwarding parameters, which may indicate an attacker attempting to establish persistence via inbox rule manipulation after hijacking a session. Associated with CVE-2026-42897 post-exploitation activity.
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Ethan Andrews@eandrews
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Federal Signal Detections
5 months ago
361641
This rule detects the creation or modification of Exchange transport rules or inbox rules that forward or redirect emails to external domains. It specifically looks for operations like 'New-TransportRule', 'Set-TransportRule', 'New-InboxRule', 'Set-InboxRule', 'Set-Mailbox', 'UpdateInboxRules', and 'Set-TransportConfig' where the destination is an email address outside of the organization's verified domains. This activity can indicate data exfiltration or an attempt to maintain persistence and collect sensitive information.
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Erik van Kruiselbergen@RideMeUp
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Detections.ai Community
5 months ago
12024
Identifies potentially malicious client-side redirects or forced OAuth flows initiating from the Outlook Web Access (OWA) interface, characterized by 302 statuses and redirect parameters. This activity may indicate post-exploitation actions related to CVE-2026-42897.
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Ethan Andrews@eandrews
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Federal Signal Detections
5 months ago
120493
Detects unusual JavaScript-related URI query parameters in Exchange IIS logs accessing the OWA directory. This may indicate attempted exploitation of the CVE-2026-42897 XSS vulnerability.
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Ethan Andrews@eandrews
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Federal Signal Detections
5 months ago
90485
Detects a temporal pattern characteristic of CVE-2026-42897 XSS exploitation: an OWA user reads a message (via Bind, OpenMessage, or similar EWS/OWA endpoints), and within 60 seconds, the same session issues a POST request to create or modify an inbox rule. This rapid succession from the same session cookie indicates programmatic action (XSS-driven JavaScript) rather than human-driven workflow. The rule correlates events by client IP and username within a 60-second window.
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Tim Peck@timpeck
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Detections.ai Community
5 months ago
180643
Detects the explicit loading of the Exchange Management snap-in by PowerShell, often a precursor to mailbox exfiltration as seen in SHADOW-EARTH-053 activity. This activity can indicate an adversary is preparing to interact with Exchange mailboxes.
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Ethan Andrews@eandrews
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Federal Signal Detections
6 months ago
60330
Identifies the creation of specific web shell filenames associated with SHADOW-EARTH-053 within targeted IIS and Exchange Web application directories. This rule detects the creation of known web shell files in critical web server paths, indicating an adversary's attempt to establish persistent access and remote control over the compromised server.
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Ethan Andrews@eandrews
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Federal Signal Detections
6 months ago
80296
This rule detects the creation or modification of Exchange inbox rules with highly suspicious or obfuscated names. Adversaries often create inbox rules with short, non-descriptive, or special character names (e.g., '.', '...', ';') to forward, redirect, or delete emails, facilitating data exfiltration or maintaining persistence. The rule specifically looks for rule names that are very short (less than 3 characters), empty, or match a predefined list of suspicious names.
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F S@Fsdr
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Detections.ai Community
6 months ago
503717
This rule detects successful sign-ins to specific Microsoft 365 applications (identified by ApplicationId '08ad6f98-a4f8-4635-bb8d-f1a3044760f0' or '07c030f6-5743-41b7-ba00-0a6e85f37c17') from devices that have previously established a network connection with a process named 'cowork-svc'. The rule correlates network connection events with Azure AD sign-in events over a 30-day lookback period to identify potentially legitimate or suspicious activity related to 'cowork-svc' application usage.
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Steven Lim@KQLWizard
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SlimKQL 2026
6 months ago
8501,087
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