Detections

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

536 detections

This rule detects inbound emails that have failed SPF and/or DKIM authentication checks and presents evidence of post-delivery user interaction. Authentication failures on inbound email are a strong indicator of email spoofing or unauthorized sending infrastructure, commonly associated with phishing campaigns targeting organizational users.
Unlike basic phishing detections that alert on email receipt alone, this rule correlates authentication failures with downstream activity to identify attacks that have progressed beyond the initial delivery phase of the MITRE ATT&CK kill chain. Specifically, the rule looks for three post-delivery indicators tied to the suspicious email:

URL Click Activity — A recipient clicked a link contained within the flagged email, suggesting potential engagement with a malicious payload or credential harvesting site
Malicious Attachment Match — An attachment delivered by the flagged email matched a known malicious SHA-256 hash present in the Threat Intelligence table, indicating a known-bad payload was delivered to the recipient
Endpoint File Creation — A file was created on an endpoint whose SHA-256 hash matches an attachment from the flagged email, suggesting the attachment was saved or executed on a host device

Any email triggering one or more of these conditions is surfaced with full metadata including sender, recipient, subject, SPF/DKIM/DMARC results, and the associated IOC for analyst review.
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Kevin Nguyen@kevin
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Detections.ai Community
5 months ago
140449
Detects when a web browser (Chrome, Edge, Firefox, Brave) spawns `cmd.exe` with a command line that includes a temporary directory path and specific command separators, indicating potential malicious copy-paste activity or drive-by compromise. The rule looks for a long command containing `&&`, `& rem`, `tar -xf`, or `rundll32` within the temporary directory.
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Daniel Jeremiah@daniyyell
Google SecOps
4 months ago
202
Detects the loading of a compromised JavaScript file from a CDN (cdn-static.okendo.io/reviews-widget-plus/js/okendo-reviews.js) followed by the execution of mshta.exe on the same device within a 10-minute timeframe, indicating a potential supply chain attack by SmartApeSG.
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Ibrahim Saud@tektrix
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Detections.ai Community
4 months ago
002
Detects network connections or DNS queries to the specific link-aggregation domain 'fanlnk.to'. This domain is known to be abused by the threat actor SniperDz to mask the destination of malicious social media lures, often leading to phishing or malware delivery.
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Duo Tech@duotech
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Detections.ai Community
5 months ago
006
Detects the creation of archive files (ZIP, RAR, 7Z) or executables with specific naming conventions (GST_, Debit_, Invoice_, NEFT_, RTGS_) often associated with Remcos RAT loaders. This rule focuses on the initial file creation event on a device.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
4 months ago
000
Identifies downstream ClickFix where users paste and execute PowerShell or CMD commands via the Explorer Run menu, specifically looking for commands that include Invoke-WebRequest, IEX, or mshta, and are associated with network connections to 'wigetticks.com' or 'wizzleticks.com'.
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Ibrahim Saud@tektrix
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Detections.ai Community
4 months ago
001
This rule detects the execution of potentially unwanted programs (PUPs) from common temporary or user-specific download directories. It specifically looks for processes with filenames indicative of PUPs (e.g., 'pua.exe', 'adware.exe', 'pup.exe', 'unwanted.exe') originating from 'Temp', 'AppData', or 'Downloads' folders. The rule aggregates these events per device per hour and alerts if one or more such executions occur, indicating potential user-initiated installation or drive-by download of unwanted software.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
4 months ago
002
Detects PowerShell processes launched by web browsers (Chrome, Edge, Firefox, Internet Explorer) or Windows Explorer, especially when using suspicious command-line arguments like encoded commands, Invoke-Expression, or web download functions. This behavior can indicate an attempt to execute malicious scripts, often initiated through user interaction (e.g., clicking a malicious link or opening a crafted file).
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
5 months ago
306
Detects users clicking malicious links that result in malware payload downloads
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
003
This rule detects attempts by users to download fake software cracks, keygens, activators, patches, or serials from HTTP servers. It specifically looks for HTTP responses containing URIs with keywords like 'crack', 'keygen', 'activator', 'patch', or 'serial' (case-insensitive) and verifies that the downloaded file data starts with 'MZ', indicating a Windows executable. This combination suggests a user is downloading potentially malicious software disguised as a legitimate software cracking tool.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
005
This rule detects executable attachments (e.g., .exe, .bat, .cmd, .scr, .pif, .com) being delivered via SMTP email. It specifically looks for these file extensions within the 'filename' attribute of email attachments.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
004
Detects the execution of commands indicative of a user pasting a malicious script into the Terminal, often associated with ClickFix or fake CAPTCHA social engineering attacks. This typically involves using tools like `curl` to download and pipe payloads directly to a shell, or the use of `pbpaste` to execute clipboard contents.
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Duo Tech@duotech
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Detections.ai Community
5 months ago
1027
Detects installation or execution of known typo-squatted npm packages linked to TeamPCP copycats (Shai-Hulud clones and DDoS botnets).
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Ravi Asakapalli@Ravishankaraskp
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Detections.ai Community
5 months ago
501,289
This rule detects attempts to download executable files disguised as common media file types (MP4, MP3, AVI, MOV) over HTTP. It specifically looks for the 'MZ' header, which indicates a Windows executable, within the first two bytes of the file data, combined with a URI ending in a media file extension. This technique is often used by attackers to bypass security controls and trick users into executing malicious payloads.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
003
This rule detects the download of a potential trojanized installer file over HTTP. It looks for HTTP responses to clients that contain 'setup', 'install', or 'installer' in the URI, have a file size greater than 500KB, and contain the 'MZ' header, indicating a Windows executable. This combination suggests a user is downloading an executable that could be malicious.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
002
This rule detects the download of archive files (ZIP, RAR, 7Z, TAR.GZ) over HTTP that contain an executable file signature ('MZ' header). This combination suggests a potential user execution scenario where a malicious executable might be delivered within an archive.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
002
This query is a security detection rule: it flags when image file operations occur in tandem with executable file operations, which is often a sign of potential malware or intrusion activity.
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Canister -@Canister
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Detections.ai Community
5 months ago
80296
Detects when a web browser (Chrome, Edge, Firefox, Brave, Opera) initiates a process that is not another instance of itself. This could indicate a drive-by download, execution of malicious code, or other suspicious activity originating from a browser.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
5 months ago
101
This rule detects when a web browser initiates the execution of an executable (.exe), dynamic link library (.dll), JavaScript (.js), or VBScript (.vbs) file. This behavior can be indicative of malicious activity such as drive-by downloads, phishing attacks leading to malware execution, or exploitation of browser vulnerabilities.
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Ankit Mehta@Secvyn
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Detections.ai Community
5 months ago
106
This rule detects a payload download after a redirect chain, which is a common technique used in user execution attacks. It specifically looks for HTTP responses containing a redirect pattern in the HTTP referer and then checks for the 'MZ' magic bytes (indicating a Windows executable) in the file data within a short depth. This suggests a user being redirected and then automatically downloading a malicious executable.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
001
This rule detects the download of files that have a 'double extension' pattern, specifically where a common document or image file extension (pdf, doc, jpg, png) is followed by an executable extension (exe, bat, vbs, ps1). This pattern is often used by attackers to trick users into executing malicious files, as the operating system might only display the first extension, making the file appear benign. The detection is based on analyzing the HTTP URI for this specific naming convention.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
001
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