Detections

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

7,270 detections

The following analytic detects the execution of the "sudo" or "su" command on a Linux operating system. It leverages data from Linux Auditd, focusing on process names and parent process names. This activity is significant because "sudo" and "su" commands are commonly used by adversaries to elevate privileges, potentially leading to unauthorized access or control over the system. If confirmed malicious, this activity could allow attackers to execute commands with root privileges, leading to severe security breaches, data exfiltration, or further system compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1050
This analytic detects suspicious command-lines that modify user profile files to automatically execute scripts or executables upon system reboot. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions involving profile files like ~/.bashrc and /etc/profile. This activity is significant as it indicates potential persistence mechanisms used by adversaries to maintain access to compromised hosts. If confirmed malicious, this could allow attackers to execute arbitrary code upon reboot, leading to persistent control over the system and potential further exploitation.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0050
This rule detects when an authorization token, initially observed in Google Kubernetes Engine (GKE) activity logs, is subsequently used within a command line on an endpoint system. This behavior suggests that a GKE pod's credential may have been exfiltrated and is being reused on a different system, potentially indicating unauthorized access or credential theft.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
1069
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
This analytic detects CrowdStrike alerts specifically categorized with a 'MEDIUM' severity. These alerts indicate suspicious activity that warrants prompt attention but is not immediately critical. Such activities might include unusual behavior or attempted policy violations. The rule processes CrowdStrike stream data, renames relevant fields for consistency, and then filters for events where the 'severity' field contains 'MEDIUM'. The primary goal is to identify and flag these medium-severity incidents for further investigation and mitigation to prevent potential escalation of attacks.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1048
The analytic detects the execution of the "swapoff" command with the "-a" argument, which disables the swapping of all paging devices on a Linux system. This activity is significant because disabling swap can be a tactic used by malware, such as Awfulshred, to evade detection and hinder forensic analysis. If confirmed malicious, this action could allow an attacker to manipulate system memory management, potentially leading to data corruption, system instability, or evasion of memory-based detection mechanisms.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0048
This analytic detects previously unseen processes within the Kubernetes environment on master or worker nodes. It leverages process metrics collected via an OTEL collector and hostmetrics receiver, with data pulled from Splunk Observability Cloud. The detection compares processes observed in the last hour against those seen in the previous 30 days. Identifying new processes is crucial as they may indicate unauthorized activity or attempts to compromise the node. If confirmed malicious, these processes could lead to data exfiltration, privilege escalation, denial-of-service attacks, or the introduction of malware, posing significant risks to the Kubernetes cluster.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0047
The analytic detects the addition of NOPASSWD entries to the /etc/sudoers file on Linux systems. It leverages Linux Auditd data to identify command lines containing "NOPASSWD:". This activity is significant because it allows users to execute commands with elevated privileges without requiring a password, which can be exploited by adversaries to maintain persistent, privileged access. If confirmed malicious, this could lead to unauthorized privilege escalation, persistent access, and potential compromise of sensitive data and system integrity.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
7046
This analytic detects the execution of the 'setcap' utility to enable the SUID bit on Linux systems. It leverages Linux Auditd data, focusing on process names and command-line arguments that indicate the use of 'setcap' with specific capabilities. This activity is significant because setting the SUID bit allows a user to temporarily gain root access, posing a substantial security risk. If confirmed malicious, an attacker could escalate privileges, execute arbitrary commands with elevated permissions, and potentially compromise the entire system.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0046
The following analytic detects suspicious modifications to cron jobs on Linux systems using the crontab command with list parameters. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity is significant as it may indicate an attempt to establish persistence or execute malicious code on a schedule. If confirmed malicious, the impact could include unauthorized code execution, data destruction, or other damaging outcomes. Further investigation should analyze the added cron job, its associated command, and any related processes.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0044
This analytic identifies the execution of Node.js with elevated privileges using `sudo`, specifically when spawning child processes. It focuses on command-line executions that include specific Node.js commands related to `child_process.spawn` and `stdio`. Running Node.js as a superuser without dropping privileges can allow unauthorized access to the file system and potential privilege escalation. If confirmed malicious, this could enable an attacker to maintain privileged access, execute arbitrary code, and compromise sensitive data within the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0044
The analytic detects attempts to stop or clear a service on Linux systems. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on processes like "systemctl," "service," and "svcadm" executing stop commands. This activity is significant as adversaries often terminate security or critical services to disable defenses or disrupt operations, as seen in malware like Industroyer2. If confirmed malicious, this could lead to the disabling of security mechanisms, allowing attackers to persist, escalate privileges, or deploy destructive payloads, severely impacting system integrity and availability.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0044
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 following analytic detects the creation of files in Linux init boot directories, which are used for automatic execution upon system startup. It leverages file system logs to identify new files in directories such as /etc/init.d/ and /etc/rc.d/. This activity is significant as it is a common persistence technique used by adversaries, malware authors, and red teamers. If confirmed malicious, this could allow an attacker to maintain persistence on the compromised host, potentially leading to further exploitation and unauthorized control over the system.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
4043
The analytic detects the use of Ngrok on a Linux operating system by monitoring process names and command-line arguments. Ngrok is a legitimate reverse proxy tool that can be used by adversaries to establish reverse proxies, potentially bypassing network defenses. If confirmed malicious, this could allow attackers to create persistent, unauthorized access channels, facilitating data exfiltration or further exploitation of the compromised system.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0043
The following analytic identifies processes running from newly seen paths within a Kubernetes environment. It leverages process metrics collected via an OTEL collector and hostmetrics receiver, and data is pulled from Splunk Observability Cloud using the Splunk Infrastructure Monitoring Add-on. This detection compares processes observed in the last hour with those seen over the previous 30 days. This activity is significant as it may indicate unauthorized changes, compromised nodes, or the introduction of malicious software. If confirmed malicious, it could lead to unauthorized process execution, control over critical resources, data exfiltration, privilege escalation, or malware introduction within the Kubernetes cluster.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0042
The following analytic detects unauthorized file creation in known crontab directories on Unix-based systems. It leverages filesystem data to identify new files in directories such as /etc/cron* and /var/spool/cron/*. This activity is significant as it may indicate an attempt by threat actors or malware to establish persistence on a compromised host. If confirmed malicious, this could allow attackers to execute arbitrary code at scheduled intervals, 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
0042
The following analytic detects suspicious attempts to find credentials stored in password managers, which may indicate an attacker's effort to retrieve sensitive login information. Password managers are often targeted by adversaries seeking to access stored passwords for further compromise or lateral movement within a network. By monitoring for unusual or unauthorized access to password manager files or processes, this analytic helps identify potential credential theft attempts, enabling security teams to respond quickly to protect critical accounts and prevent further unauthorized access.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0042
The following analytic identifies the execution of common Linux processes used for elevation control, such as `chmod`, `chown`, and `setuid`. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity is significant because these processes are often abused by adversaries to gain persistence or escalate privileges on compromised hosts. If confirmed malicious, this behavior could allow attackers to modify file attributes, change file ownership, or set user IDs, potentially leading to unauthorized access and control over critical system resources.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0042
This analytic detects the creation of new files within the Linux kernel/driver directory. This activity is significant because this directory is typically reserved for kernel modules, and unauthorized file creation here can indicate a rootkit installation. If confirmed malicious, this could allow an attacker to gain high-level privileges, potentially compromising the entire system by executing code at the kernel level.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1042
The analytic detects the execution of the SysRq hack to reboot a Linux system host. It identifies processes executing the command to pipe 'b' to /proc/sysrq-trigger. This activity is significant as it is an uncommon method to reboot a system and was observed in the Awfulshred malware wiper. If confirmed malicious, this technique could indicate the presence of suspicious processes and potential system compromise, leading to unauthorized reboots and disruption of services.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0042
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