Detections

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

1,735 detections

This rule detects emails sent over SMTP where the 'From:' and 'Reply-To:' headers are present, indicating a potential attempt to spoof the sender's display name while using a different domain. It triggers an alert if 10 such emails are observed from the same source within 60 seconds, suggesting a bulk email or phishing attempt.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
003
This rule detects email spoofing attempts where the 'From' address domain does not match the 'Return-Path' address domain. It specifically looks for SMTP traffic on port 25, ensuring the flow is established and to the server. The rule uses PCRE to extract the domain from the 'From' header and then checks if the 'Return-Path' header contains a different domain.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
003
Detects DNS queries to privnote.com, which UNC3753 uses to transmit self-destructing text containing malicious installation links to targets.
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Duo Tech@duotech
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Detections.ai Community
5 months ago
007
Detects the presence of 'search:' or 'search-ms:' URI schemes embedded in inbound emails. These schemes can be abused to force outbound NTLM authentication and leak Net-NTLMv2 hashes via a single link click.
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Ethan Andrews@eandrews
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Federal Signal Detections
5 months ago
12028
This rule detects potential reverse proxy phishing pages by looking for HTTP URI requests that contain the keywords 'verify', 'account', and 'secure' (case-insensitive). The presence of these keywords in the URI of an HTTP request, particularly when combined, can indicate an attempt to mimic legitimate login or account verification pages, often used in phishing attacks.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
004
This rule detects phishing emails sent over SMTP that contain macro-enabled documents (Word or Excel files) as attachments. It specifically looks for base64 encoded content, the 'filename=' attribute, and uses a PCRE to identify common macro-enabled file extensions like .doc, .docx, .xls, .xlsm, and .xlsb within the filename.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
004
This rule detects HTTP traffic where the URI contains common URL shortener domains (bit.ly, tinyurl, t.co, ow.ly, is.gd) and also contains the string "login" (case-insensitive). This combination is often indicative of phishing attempts that use URL shorteners to obscure malicious links, leading users to fake login pages.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
004
This rule detects phishing emails that deliver survey or form lures by identifying specific content patterns within SMTP traffic. It looks for emails with 'Content-Type: application/' and 'filename=' headers, specifically targeting attachments with file extensions like .doc, .docx, .pdf, or .xlsx, which are commonly used in social engineering attacks to deliver malicious documents or forms.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
004
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 emails where the sender's address contains keywords like 'paypal', 'amazon', or 'apple' but does not originate from their official domains (e.g., '@paypal.com'). This pattern is indicative of lookalike domain phishing attempts, where attackers try to impersonate legitimate brands to trick recipients.
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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
This rule detects web pages that are likely part of a bank vishing callback scam. It looks for HTTP responses (flow:to_client) containing the keywords 'call', 'toll-free', and 'account' (case-insensitive) in the file data. This combination of keywords suggests a page designed to trick users into calling a fraudulent number to discuss their 'account'.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
003
This rule detects spearphishing emails sent over SMTP that contain an Office document attachment. It specifically looks for emails with a 'Content-Type: application/' header, a 'filename=' attribute, and the '.docx' extension in the content, indicating a Microsoft Word document.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
003
This rule detects attempts to harvest credentials using a fake Microsoft login page. It triggers when HTTP traffic from the server to the client contains both "microsoftonline" and "password" in the file data, and the HTTP host is an IP address. This combination suggests a phishing attempt where a malicious server is impersonating a Microsoft login page to capture user credentials.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
003
This rule detects potential phishing attempts delivered via Slack messages. It triggers when HTTP traffic to 'slack.com' contains '/messages/' in the URI, indicating a Slack message context, and has a threshold of 5 occurrences within 60 seconds from the same source.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
002
Detects inbound emails with voicemail-themed subjects that pass SPF and DKIM but fail DMARC alignment. This technique is often used to exploit domains with p=none policies and obscure the actual origin of phishing attempts.
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Ethan Andrews@eandrews
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Federal Signal Detections
5 months ago
5014
This rule detects network connections or URL click events to a list of domains known to be associated with phishing or malware distribution. The rule specifically looks for connections to these domains that also contain certain path segments like '/wlc/', '/load/', or '/success/', which are often indicative of malicious activity or payload delivery. It also broadly checks for any URL click events containing these suspicious domains.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
5 months ago
001
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
Bharat Cyber Guardians
5 months ago
001
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