Detections

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

599 detections

This analytic identifies suspicious DNS TXT records using a pre-trained deep learning model. It leverages DNS response data from the Network Resolution data model, categorizing TXT records into known types via regular expressions. Records that do not match known patterns are flagged as suspicious. This activity is significant as DNS TXT records can be used for data exfiltration or command-and-control communication. If confirmed malicious, attackers could use these records to covertly transfer data or receive instructions, posing a severe threat to network security.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1051
The analytic detects multiple CrowdStrike LOW severity alerts originating from the same endpoint, indicating a series of minor suspicious activities or policy violations. Specifically, it triggers when an endpoint generates three or more distinct types of LOW severity alerts. These alerts are not immediately critical but should be reviewed to prevent potential threats. They often highlight unusual behavior or low-level risks that, if left unchecked, could escalate into more significant security issues. Regular monitoring and analysis of these alerts are essential for maintaining robust security, as a cluster of different low-severity events can be an early indicator of a more significant compromise or an adversary's reconnaissance activities.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1049
The following analytic detects the use of the .NET compiler csc.exe for on-the-fly compilation of potentially malicious .NET code. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on specific command-line patterns associated with csc.exe. This activity is significant because adversaries and malware often use this technique to evade detection by compiling malicious code at runtime. If confirmed malicious, this could allow attackers to execute arbitrary code, potentially leading to system compromise, data exfiltration, or further lateral movement within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0048
The analytic identifies potential exploitation of Log4Shell CVE-2021-44228 by correlating multiple MITRE ATT&CK tactics detected in risk events. It leverages Splunk's risk data model to calculate the distinct count of MITRE ATT&CK tactics from Log4Shell-related detections. This activity is significant because it indicates a high probability of exploitation if two or more distinct tactics are observed. If confirmed malicious, this activity could lead to initial payload delivery, callback to a malicious server, and post-exploitation activities, potentially resulting in unauthorized access, lateral movement, and further compromise of the affected systems.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0047
The following analytic detects the use of Regsvr32.exe to register DLLs from suspicious paths such as AppData, ProgramData, or Windows Temp directories. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs and command-line arguments. This activity is significant because Regsvr32.exe can be abused to proxy execution of malicious code, bypassing traditional security controls. If confirmed malicious, this could allow an attacker to execute arbitrary code, potentially leading to system compromise, data exfiltration, or further lateral movement within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0046
This analytic identifies attempts to exploit the CVE-2023-46805 and CVE-2024-21887 vulnerabilities in Ivanti Connect Secure. It detects GET requests to the `/api/v1/totp/user-backup-code/../../system/system-information` URI, which leverage an authentication bypass to access system information. The detection uses the Web datamodel to identify requests with a 200 OK response, indicating a successful exploit attempt. This activity is significant as it reveals potential unauthorized access to sensitive system information. If confirmed malicious, attackers could gain critical insights into the system, facilitating further exploitation and compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2046
This detection identifies potential exploitation of CVE-2025-24813 in Apache Tomcat through the initial stage of the attack. This first phase occurs when an attacker attempts to upload a malicious serialized Java object with a .session file extension via an HTTP PUT request. When successful, these uploads typically result in HTTP status codes 201 (Created) or 409 (Conflict) and create the foundation for subsequent deserialization attacks by placing malicious content in a location where Tomcat's session management can access it.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0044
The analytic detects instances of `regsvcs.exe` running without command line arguments. This behavior typically indicates process injection, where another process manipulates `regsvcs.exe`. The detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names, IDs, and command-line executions. This activity is significant as it may signal an attempt to evade detection and execute malicious code. If confirmed malicious, the attacker could achieve code execution, potentially leading to privilege escalation, persistence, or access to sensitive information.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0043
The following analytic detects the execution of "dsquery.exe" with arguments targeting `TrustedDomain` queries directly from the command line. This behavior is identified using Endpoint Detection and Response (EDR) telemetry, focusing on process names and command-line arguments. This activity is significant as it often indicates domain trust discovery, a common step in lateral movement or privilege escalation by adversaries. If confirmed malicious, this could allow attackers to map domain trusts, potentially leading to further exploitation and unauthorized access to trusted domains.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0043
The analytic identifies access to a specific Ivanti Connect Secure endpoint, `/api/v1/configuration/users/user-roles/user-role/rest-userrole1/web/web-bookmarks/bookmark`, which is known to be vulnerable to CVE-2023-46805 and CVE-2024-21887. It specifically looks for GET requests that result in a 403 Forbidden HTTP status code with an empty response body. This behavior is indicative of potential exploitation attempts against Ivanti Connect Secure systems. Successful exploitation could lead to unauthorized access or control, potentially resulting in data breaches or system compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1043
The following analytic detects the presence of punycode within x509 certificates using Zeek x509 logs. It identifies punycode in the subject alternative name email and other fields by searching for the "xn--" prefix. This activity is significant as punycode can be used in phishing attacks or to bypass domain filters, posing a security risk. If confirmed malicious, attackers could use these certificates to impersonate legitimate domains, potentially leading to unauthorized access or data breaches.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0042
The analytic identifies potential exploitation attempts against Citrix ADC related to CVE-2023-3519. It detects POST requests to specific web endpoints associated with this vulnerability by leveraging the Web datamodel. This activity is significant as CVE-2023-3519 involves a SAML processing overflow issue that can lead to memory corruption, posing a high risk. If confirmed malicious, attackers could exploit this to execute arbitrary code, escalate privileges, or disrupt services, making it crucial for SOC analysts to monitor and investigate these alerts promptly.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2042
The analytic identifies potential exploitation of CVE-2023-20198 in the Web User Interface of Cisco IOS XE software. It detects suspicious activity involving specific URL patterns and HTTP methods, indicative of unauthorized administrative access and potential implant deployment. This activity can lead to full control of the device, compromising its integrity and security.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0040
The following analytic detects CrowdStrike alerts for Medium Identity Risk Severity with a risk score of 55% or higher. These alerts indicate significant vulnerabilities in user identities, such as suspicious behavior or compromised credentials. Promptly investigating and addressing these alerts is crucial to prevent potential security breaches and ensure the integrity and protection of sensitive information and systems.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1039
The following analytic detects the use of the 'dd' command to overwrite files on a Linux system. It leverages data from Linux Auditd telemetry, focusing on process execution logs that include command-line details. This activity is significant because adversaries often use the 'dd' command to destroy or irreversibly overwrite files, disrupting system availability and services. If confirmed malicious, this behavior could lead to data destruction, making recovery difficult and potentially causing significant operational disruptions.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0039
The following analytic detects suspicious use of the `modprobe` command to unload kernel modules, which may indicate an attempt to disable critical system components or evade detection. The `modprobe` utility manages kernel modules, and unauthorized unloading of modules can disrupt system security features, remove logging capabilities, or conceal malicious activities. By monitoring for unusual or unauthorized `modprobe` operations involving module unloading, this analytic helps identify potential tampering with kernel functionality, enabling security teams to investigate and address possible threats to system integrity.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0038
The analytic detects remote file inclusion (RFI) attacks targeting Kubernetes Nginx ingress controllers. It leverages Kubernetes logs from the Nginx ingress controller, parsing fields such as `remote_addr`, `request`, and `url` to identify suspicious activity. This activity is significant because RFI attacks can allow attackers to execute arbitrary code or access sensitive files on the server. If confirmed malicious, this could lead to unauthorized access, data exfiltration, or further compromise of the Kubernetes environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0037
The analytic detects potential exploitation attempts of the Log4Shell vulnerability (CVE-2021-44228) by analyzing HTTP headers for specific patterns. It leverages the Web Datamodel and evaluates various indicators such as the presence of `{jndi:`, environment variables, and common URI paths. This detection is significant as Log4Shell allows remote code execution, posing a severe threat to systems. If confirmed malicious, attackers could gain unauthorized access, execute arbitrary code, and potentially compromise sensitive data, leading to extensive damage and data breaches.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0037
This analytic detects the execution of the 'shred' command on a Linux machine, which is used to overwrite files to make them unrecoverable. It leverages data from Linux Auditd, focusing on process names and command-line arguments. This activity is significant because the 'shred' command can be used in destructive attacks, such as those seen in the Industroyer2 malware targeting energy facilities. If confirmed malicious, this activity could lead to the permanent destruction of critical files, severely impacting system integrity and data availability.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0036
The analytic identifies modifications to the registry path .wav\\OpenWithProgIds, associated with the Snake Malware campaign. This activity is significant because Snake's WerFault.exe uses this registry path to decrypt an encrypted blob containing critical components like the AES key, IV, and paths for its kernel driver and loader. If confirmed malicious, this could allow the attacker to load and execute Snake's kernel driver, leading to potential system compromise and persistent access.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0036
The following analytic detects attempts to exploit CVE-2022-26134, an unauthenticated remote code execution vulnerability in Confluence. It leverages the Web datamodel to analyze network and CIM-compliant web logs, identifying suspicious URL patterns and parameters indicative of exploitation attempts. This activity is significant as it allows attackers to execute arbitrary code on the Confluence server without authentication, potentially leading to full system compromise. If confirmed malicious, this could result in unauthorized access, data exfiltration, and further lateral movement within the network. Immediate investigation and remediation are crucial to prevent extensive damage.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0036
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