Detections

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

3,141 detections

Detects creation of email auto-forwarding rules for persistent email collection
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
002
This rule detects a high volume of successful sign-in attempts to Exchange Online from a single IP address where the UserPrincipalName ends with '@' (indicating an anonymous or malformed UPN) and Conditional Access was not applied. This pattern can be indicative of anonymous SMTP relay abuse, often used for spamming or phishing campaigns.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
5 months ago
003
This rule detects potential phishing attempts impersonating Adobe Document Cloud. It looks for emails with subjects containing keywords like "Adobe", "Document Cloud", "Sign Document", or "View Document", but where the sender's domain is NOT a legitimate Adobe domain (adobe.com or documentcloud.adobe.com). The rule then counts these occurrences per sender address and domain over a daily period.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
5 months ago
103
This rule detects emails containing archive file attachments (zip, rar, 7z). It summarizes the count of such archives per sender, recipient, and file name over a daily period. The rule specifically looks for instances where at least one archive is present in an email.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
5 months ago
003
This rule detects potential spearphishing attempts targeting high-value individuals (CEO, CFO, IT Admin) within an organization. It looks for emails sent to these individuals with subjects commonly associated with financial phishing or social engineering lures, such as "Invoice," "Wire Transfer," "Payment," "Urgent," or "Purchase Order." The rule also checks if these emails contain attachments, which is a common vector for delivering malware or credential harvesting documents in phishing campaigns. It summarizes the attempts by sender, recipient, and day, counting the number of attempts and listing the attachments.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
5 months ago
103
Detects the creation or modification of inbox rules that forward or redirect emails to another recipient. This can be an indicator of an adversary attempting to exfiltrate emails or maintain persistence.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
5 months ago
003
Detects emails containing attachments with suspicious file extensions such as '.exe', '.scr', or '.vbs'. These file types are commonly used in phishing and malware delivery campaigns.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
5 months ago
003
This rule detects the creation of new transport rules within Exchange Online. Adversaries may create malicious transport rules to forward emails, bypass security controls, or exfiltrate data. Monitoring the creation of new transport rules can help identify suspicious activity.
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Ankit Mehta@Secvyn
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Detections.ai Community
5 months ago
002
This rule detects a high volume of HTTP requests to graph.microsoft.com with the URI containing '/messages', indicating a potential bulk download of emails from Office 365 via the Graph API. The threshold is set to 30 requests within 60 seconds from a single source IP.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
003
Detects successful device code authentications specifically for the Microsoft Office application (AppId d3590ed6-52b3-4102-aeff-aad2292ab01c) that do not originate from trusted named locations. This can indicate a device code phishing attempt where an attacker has tricked a user into authenticating to a malicious application.
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Ethan Andrews@eandrews
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Federal Signal Detections
5 months ago
6017
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 potential 'impossible travel' scenarios within Azure AD sign-in logs. It identifies users who successfully sign in to Office 365 from two geographically distant IP addresses within a one-hour window, suggesting a potential compromise or an attempt to bypass security controls.
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Ankit Mehta@Secvyn
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Detections.ai Community
5 months ago
002
This rule detects attempts to add email delegate permissions via the Microsoft Graph API. It specifically looks for HTTP PATCH requests to 'graph.microsoft.com' with a URI containing 'mailboxSettings'. This activity could indicate an attacker attempting to gain unauthorized access to a user's mailbox by granting delegate access to another account, which is a common persistence technique.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
003
This rule detects emails with subjects related to financial transactions (Invoice, Purchase Order, PO, Payment, Order) that contain attachments with suspicious file extensions (.js, .hta, .vbs). It specifically filters for emails originating from domains not whitelisted as trusted and aggregates the count and average size of such attachments.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
5 months ago
002
This rule detects potential spear phishing campaigns by identifying a high volume of emails (10 or more within an hour) from external senders (not @company.com) that contain keywords like 'password', 'account', or 'security' in the subject line, and also include either an attachment or a URL. This combination of factors suggests a targeted social engineering attempt.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
5 months ago
002
This rule detects potential bulk phishing email campaigns by identifying a high volume of emails originating from external senders (not @company.com) with suspicious subject lines containing keywords like 'action required', 'verify account', or 'confirm identity'. The rule triggers if at least 50 such emails are sent to 20 or more unique recipients within a one-hour window.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
5 months ago
002
This rule detects a high volume (5 or more within an hour) of emails from the same sender containing compressed attachments (.zip, .rar, .7z) and subjects indicating documents, invoices, or reports. This pattern can be indicative of phishing campaigns attempting to deliver malware or gather information.
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Ankit Mehta@Secvyn
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Detections.ai Community
5 months ago
002
This rule detects potential phishing attempts by identifying emails with URLs that originate from outside the internal company domain (@company.com). It specifically looks for emails where the subject line contains keywords like 'click', 'confirm', or 'update', and where multiple such emails (3 or more) are sent from the same external sender to the same recipient.
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Ankit Mehta@Secvyn
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Detections.ai Community
5 months ago
002
Detects a successful login from a non-compliant, unmanaged device followed by an inbox rule creation or modification within 10 minutes. This sequence aligns with post-compromise evasion tactics observed in device code phishing campaigns like Kali365, where attackers quickly suppress security alerts after gaining access.
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Bryant Smith@flowstate
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Detections.ai Community
5 months ago
5038
This rule detects attempts to create or modify email forwarding rules in Office 365 via the Microsoft Graph API. Specifically, it looks for HTTP POST requests to the '/mailFolders/inbox/messageRules' endpoint on 'graph.microsoft.com'. This activity can indicate an attacker setting up an inbox rule to forward emails to an external address for data exfiltration or to maintain persistence.
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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
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