Detections

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

93 detections

Detects suspicious DNS queries to external service interaction domains often used for out-of-band interactions after successful RCE
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
15 days ago
1025
Detects DNS queries for the domain 'pdf.gusercontent.com', which is known to be used as a lookalike domain for Google-related services to deceive users. This pattern is often indicative of malicious infrastructure used for credential harvesting, phishing, or malware delivery.
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Ankit Mehta@Secvyn
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Detections.ai Community
1 month ago
002
Detects DNS resolution attempts for graph.microsoft.com by processes other than standard web browsers or mail clients. This activity is indicative of scripted tools or malicious software attempting to enumerate or access Microsoft 365 mailbox content via the Graph API, bypassing normal user interaction.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
001
Detects DNS queries to Gofile infrastructure originating from processes executing from typically transient directories (AppData or Temp). This behavior is characteristic of VILE ransomware, which stages compressed user files in these directories before exfiltrating them via Gofile as part of a double-extortion strategy.
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Ibrahim Saud@tektrix
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Detections.ai Community
4 months ago
307
This rule detects suspicious network activity related to Tailscale mesh VPN and DuckDNS, specifically looking for resolutions of 'tailscale.com', 'wawsenti.duckdns.org', or 'duckdns.org' via DNS events, and network flow to known C2 IPs (217.154.217.139, 217.154.162.45), or traffic on UDP port 41641 within the Tailscale IP range (100.64.0.0/10). It also flags connections to 'wawsenti.duckdns.org' or any 'duckdns.org' domain in network flow data. The rule aims to identify potential C2 communications or unauthorized use of VPN services.
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Ibrahim Saud@tektrix
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Detections.ai Community
4 months ago
102
Detects PowerShell making DNS requests for domains associated with less-reputable/uncommon TLDs. This behavior is not typical for legitimate administrative scripts and can indicate an attempt to download a payload from a malicious source.
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Tim Peck@timpeck
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Detections.ai Community
10 months ago
62166
Detects DNS queries to domains using common AWS typosquatting patterns such as 'awscloud', 'compute-aws', or billing/security lures.
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Jorden Smith@Jorden
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SimSpace Public
10 months ago
2141
Detects DNS query requests to Visual Studio Code tunnel domains. Attackers can abuse that feature to establish a reverse shell or persistence on a machine.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
11 months ago
000
Detects a program that invoked suspicious DNS queries known from Cobalt Strike beacons
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
000
The following analytic detects the use of default or publicly known named pipes associated with Cobalt Strike. It leverages Sysmon EventID 17 and 18 to identify specific named pipes commonly used by Cobalt Strike's Artifact Kit and Malleable C2 Profiles. This activity is significant because Cobalt Strike is a popular tool for adversaries to conduct post-exploitation tasks, and identifying its named pipes can reveal potential malicious activity. If confirmed malicious, this could indicate an active Cobalt Strike beacon, leading to unauthorized access, data exfiltration, or further lateral movement within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
100247
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
This analytic detects suspicious data transfer activities involving the use of the `split` syscall with the `-b` option, which specifies the size of each output file. This technique can be used by attackers to evade detection by breaking large files into smaller parts, bypassing size-based security controls, and facilitating covert exfiltration of sensitive data. By monitoring for unusual or unauthorized use of the `split` syscall with a specified block size, this analytic helps identify potential data exfiltration attempts.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0087
This analytic identifies the bulk creation of ransomware notes (e.g., .txt, .html, .hta files) on an infected machine. It leverages Sysmon EventCode 11 to detect multiple instances of these file types being created within a short time frame (10 seconds). A detection is triggered if 15 or more unique readme paths are observed. This activity is a strong indicator of an active ransomware attack, where the attacker is notifying the victim of the encryption. If confirmed malicious, this behavior could lead to widespread data encryption, rendering critical files inaccessible and potentially causing significant operational disruption.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1160
The following analytic detects suspicious attempts to find credentials stored in password stores, indicating a potential attacker's effort to access sensitive login information. Password stores are critical repositories that contain valuable credentials, and unauthorized access to them can lead to significant security breaches. By monitoring for unusual or unauthorized activities related to password store access, this analytic helps identify potential credential theft attempts, allowing security teams to respond promptly and prevent unauthorized access to critical systems and data.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0056
Detects DNS queries containing patterns associated with Kerberos coercion attacks via DNS object spoofing.
The pattern "1UWhRCAAAAA..BAAAA" is a base64-encoded signature that corresponds to a marshaled CREDENTIAL_TARGET_INFORMATION structure.
Attackers can use this technique to coerce authentication from victim systems to attacker-controlled hosts.
It is one of the strong indicators of a Kerberos coercion attack, where adversaries manipulate DNS records
to spoof Service Principal Names (SPNs) and redirect authentication requests like CVE-2025-33073.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
005
The following analytic detects the creation of files in the Windows %startup% folder, a common persistence technique. It leverages the Endpoint.Filesystem data model to identify file creation events in this specific directory. This activity is significant because adversaries often use the startup folder to ensure their malicious code executes automatically upon system boot or user logon. If confirmed malicious, this could allow attackers to maintain persistence on the host, potentially leading to further system compromise and unauthorized access to sensitive information.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0044
The following analytic identifies the creation of executables or scripts in suspicious file paths on Windows systems. It leverages the Endpoint.Filesystem data model to detect files with specific extensions (e.g., .exe, .dll, .ps1) created in uncommon directories (e.g., \windows\fonts\, \users\public\). This activity is significant as adversaries often use these paths to evade detection and maintain persistence. If confirmed malicious, this behavior could allow attackers to execute unauthorized code, escalate privileges, or persist within the environment, posing a significant security threat.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1071
This rule detects DNS resolution attempts for domains associated with Tor onion services and Tor2web gateways. It specifically looks for DNS queries ending with various Tor-related top-level domains and subdomains, indicating potential use of the Tor network for anonymization or accessing hidden services.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0030
Detects DNS resolution of an .onion address related to Tor routing networks
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
000
This analytic detects the configuration of TFTP services on Cisco IOS devices that could be used to exfiltrate sensitive configuration files. Threat actors like Static Tundra have been observed configuring TFTP servers to make device configuration files accessible for exfiltration after gaining initial access. The detection specifically looks for commands that expose critical configuration files such as startup-config, running-config, and other sensitive system information through TFTP. This activity is particularly concerning as it may represent an attempt to steal credentials, network topology information, and other sensitive data stored in device configurations.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1059
Detects DNS query requests to Devtunnels domains. Attackers can abuse that feature to establish a reverse shell or persistence on a machine. Devtunnels can be used for command and control or data exfiltration by tunneling traffic over legitimate-looking DNS requests.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
1029
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