Detections

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

696 detections

Detects the execution of the 'curl.exe' process with specific flags that indicate an attempt to upload or exfiltrate data. This includes flags like '--form', '--upload-file', '--data', and variations of '--data-' (e.g., '--data-ascii', '--data-binary', '--data-raw', '--data-urlencode'), as well as shorthand flags like '-F', '-T', and '-d'. The rule filters out connections to localhost to reduce false positives.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0027
Detects unauthorized access attempts to a resource.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
001
These rules detect indicators associated with a campaign where attackers compromised developer accounts and inserted malicious code into over 35 Google Chrome extensions. The first rule identifies suspicious network connections to known malicious IP addresses and command-and-control (C2) domains. The second rule identifies the presence of known malicious Chrome extension names or their corresponding extension IDs, which could indicate the presence of a hijacked extension.
100daysofyara 2025@100daysyara2025
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100 Days of YARA 2025
1 year ago
1062
Detects when a transfer lock was removed from an AWS Route 53 domain. This action is typically performed when intending to transfer the domain to a different registrar, but it can also be an indicator of malicious activity if unauthorized. Disabling the transfer lock makes the domain vulnerable to unauthorized transfers, which could lead to domain hijacking or redirection of traffic.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0022
Detects a DNS server error indicating that a specified plugin DLL, configured in the registry, could not be loaded. This event can be triggered by an attacker attempting to load a malicious DLL for privilege escalation or persistence on a DNS server, often associated with techniques like DNSAdmin to DC compromise.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0021
Detects when full data export is attempted an unauthorized user.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
000
Detects agentic AI jailbreak attempts that try to establish persistent control over M365 Copilot through rule injection, universal triggers, response automation, system overrides, and persona establishment techniques. The detection analyzes the PromptText field for keywords like "from now on," "always respond," "ignore previous," "new rule," "override," and role-playing commands (e.g., "act as," "you are now") that attempt to inject persistent instructions. The search computes risk by counting distinct jailbreak indicators per user session, flagging coordinated manipulation attempts.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1084
Detects M365 Copilot users exhibiting suspicious application usage patterns including multi-location access, abnormally high activity volumes, or access to multiple Copilot applications that may indicate account compromise or automated abuse. The detection aggregates M365 Copilot Graph API events per user, calculating metrics like distinct cities/countries accessed, unique IP addresses, number of different Copilot apps used, and average events per day over the observation period. Users are flagged when they access Copilot from multiple cities (cities_count > 1), generate excessive daily activity (events_per_day > 100), or use more than two different Copilot applications (app_count > 2), which are anomalous patterns suggesting credential compromise or bot-driven abuse.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0075
Detects the import or deletion of key material in AWS KMS, which can be used as part of ransomware attacks. This activity is uncommon and provides a high certainty signal.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
000
The following analytic detects the use of certutil.exe to add a certificate to the Root certificate store using the "-addstore" flag. In this case, the certificate is loaded from a temporary file path (e.g., %TEMP%) or other uncommon locations (e.g. C:\Users\Public\), which is highly suspicious and uncommon in legitimate administrative activity. This behavior may indicate an adversary is installing a malicious root certificate to intercept HTTPS traffic, impersonate trusted entities, or bypass security controls. The use of flags such as -f (force) and -Enterprise, combined with loading .tmp files from user-writable locations, is consistent with post-exploitation activity seen in credential theft and adversary-in-the-middle (AiTM) attacks. This should be investigated immediately, especially if correlated with unauthorized privilege use or prior certificate modifications. You should monitor when new certificates are added to the root store because this store is what your system uses to decide which websites, apps, and software can be trusted. If an attacker manages to add their own certificate there, they can silently intercept encrypted traffic, impersonate trusted websites, or make malicious programs look safe. This means they could steal sensitive data, bypass security tools, and keep access to your system even after other malware is removed.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0040
This rule detects URLs that contain common redirection or link parameters (u=, url=, redirect=, r=, link=, target=, dest=) where the value of the parameter is a long, alphanumeric string that appears to be an encoded domain. This pattern can indicate attempts to obfuscate the true destination of a link, often seen in phishing campaigns or malicious redirection attempts. The rule specifically looks for encoded parameters containing common top-level domains like .com, .net, or .org.
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Ankit Mehta@Secvyn
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Detections.ai Community
1 year ago
264308
This rule detects successful or failed logon attempts originating from IP addresses identified by threat intelligence as associated with botnets, command and control (C2) infrastructure, or proxies. The rule specifically looks for 'LogOn' or 'FailedLogOn' activity types where the source IP's threat intelligence indicator type is 'Botnet', 'C2', or 'Proxy', and where activity insights are available.
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Ankit Mehta@Secvyn
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Detections.ai Community
1 year ago
130160
This rule identifies Cisco network devices within Microsoft Defender for Endpoint (MDE) telemetry that are running Cisco IOS or Cisco XE operating systems, excluding version '17.15.4a'. The exclusion of a specific OS version suggests the rule is designed to pinpoint devices that may be vulnerable to a known security flaw, potentially CVE-2025-20352 as indicated by the rule's title. It helps in mapping exposure to specific vulnerabilities by identifying potentially unpatched or vulnerable network infrastructure components.
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Steven Lim@KQLWizard
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SlimKQL
1 year ago
145954
The following analytic detects potential distributed password spraying attacks in an Azure AD environment. It identifies a spike in failed authentication attempts across various user-and-IP combinations from multiple source IPs and countries, using different user agents. This detection leverages Azure AD SignInLogs, focusing on error code 50126 for failed authentications. This activity is significant as it indicates an adversary's attempt to bypass security controls by distributing login attempts. If confirmed malicious, this could lead to unauthorized access, data breaches, privilege escalation, and lateral movement within the organization's infrastructure.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0042
This detection rule identifies potential SEO poisoning activity associated with the Operation Rewrite campaign. It looks for a high volume of web requests from a single source IP where the HTTP referrer indicates the traffic originated from a search engine. This pattern can indicate a compromised host being used for malicious purposes or a user interacting with multiple poisoned search results.
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Kenji Choy@kchoy
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Detections.ai Community
1 year ago
60186
Detects files containing Command and Control (C2) domains and IP addresses associated with the 'Operation Rewrite' SEO poisoning campaign (CL-UNK-1037). These indicators are often found embedded in BadIIS malware variants or related configuration files.
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Matt Brady@mbrady5299
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Detections.ai Community
1 year ago
1180
Detects potential Cloudflare Under Attack Mode (UAM) bypass activity, characteristic of the ShadowV2 botnet. This involves the execution of a headless browser followed by network requests using a Cloudflare clearance cookie.
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Tim Peck@timpeck
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Detections.ai Community
1 year ago
0089
Detects the managed .NET IIS module variant of BadIIS, used in the 'Operation Rewrite' campaign for SEO poisoning and traffic redirection.
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Matt Brady@mbrady5299
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Detections.ai Community
1 year ago
1054
Detects BadIIS malware variants associated with the 'Operation Rewrite' campaign (CL-UNK-1037). This rule identifies the native IIS module, PHP backdoors, and other related components used for SEO poisoning.
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Matt Brady@mbrady5299
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Detections.ai Community
1 year ago
0037
Detects the ASP.NET page handler (webshell) used in the 'Operation Rewrite' campaign for SEO poisoning and traffic redirection.
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Matt Brady@mbrady5299
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Detections.ai Community
1 year ago
0035
This rule detects the download or installation of known malicious NPM package versions by monitoring process command-line arguments for specific package names and versions. It targets common package managers like npm, yarn, and pnpm, as well as node.exe, to identify instances where a compromised or intentionally malicious package is being introduced into a development or production environment.
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Elgonad .@elgonad
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Detections.ai Community
1 year ago
131357
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