Detections

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

7,138 detections

The following analytic detects the execution of the "sudo" or "su" command on a Linux operating system. It leverages data from Endpoint Detection and Response (EDR) agents, 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
0036
The following analytic detects a high frequency of file deletions in the /boot/ folder on Linux systems. It leverages filesystem event logs to identify when 200 or more files are deleted within an hour by the same process. This behavior is significant as it may indicate the presence of wiper malware, such as Industroyer2, which targets critical system directories. If confirmed malicious, this activity could lead to system instability or failure, hindering the boot process and potentially causing a complete system compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0035
The analytic detects suspicious command-line activity that modifies the iptables firewall settings on a Linux machine. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on specific command patterns that alter firewall rules to accept traffic on certain TCP ports. This activity is significant as it can indicate malware, such as CyclopsBlink, modifying firewall settings to allow communication with a Command and Control (C2) server. If confirmed malicious, this could enable attackers to maintain persistent access and exfiltrate data, posing a severe security risk.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0035
The following analytic detects the execution of the chmod utility to set the SUID or SGID bit on files, which can allow users to temporarily gain root or group-level access. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line arguments related to chmod. This activity is significant as it can indicate an attempt to escalate privileges or maintain persistence on a system. If confirmed malicious, an attacker could gain elevated access, potentially compromising sensitive data or critical system functions.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0035
The following analytic detects the execution of the 'setcap' utility to enable the SUID bit on Linux systems. It leverages Endpoint Detection and Response (EDR) 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
0035
The analytic detects the use of the Linux 'xclip' command to copy data from the clipboard. It leverages Linux Auditd telemetry, focusing on process names and command-line arguments related to clipboard operations. This activity is significant because adversaries can exploit clipboard data to capture sensitive information such as passwords or IP addresses. If confirmed malicious, this technique could lead to unauthorized data exfiltration, compromising sensitive information and potentially aiding further attacks within the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0034
The analytic detects the execution of the 'c89' command with elevated privileges, specifically when used in conjunction with 'sudo' and a '-wrapper' argument. This activity indicates a potential privilege escalation attempt on Linux systems, allowing a user to compile and execute C programs as root. Successful exploitation could lead to full system compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0034
The analytic detects the use of the 'cpulimit' command with specific flags ('-l', '-f') executed with 'sudo' privileges on Linux systems. This activity is significant because if 'cpulimit' is granted sudo rights, a user can potentially execute system commands as root, leading to privilege escalation. If confirmed malicious, this could allow an attacker to gain root access, execute arbitrary commands, and fully compromise the affected system.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0034
This analytic detects the behavior of decoding base64-encoded data and passing it to a Linux shell. The detection is made by searching for specific commands in the Splunk query, namely "base64 -d" and "base64 --decode", within the Endpoint.Processes data model. The analytic also includes a filter for Linux shells. This activity is indicative of malicious behavior as Base64 encoding is commonly used to obfuscate malicious commands or payloads, and decoding it can be a step in running those commands. It suggests that an attacker is attempting to run malicious commands on a Linux system to gain unauthorized access, for data exfiltration, or perform other malicious actions.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0034
The following analytic detects the deletion of init daemon scripts on a Linux machine. It leverages filesystem event logs to identify when files within the /etc/init.d/ directory are deleted. This activity is significant because init daemon scripts control the start and stop of critical services, and their deletion can indicate an attempt to impair security features or evade defenses. If confirmed malicious, this behavior could allow an attacker to disrupt essential services, execute destructive payloads, or persist undetected in the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0034
The analytic detects the suspicious editing of cron jobs in Linux using the `crontab` command-line parameter (`-e`). It identifies this activity by monitoring command-line executions involving 'crontab' and the edit parameter. This behavior is significant for a SOC as cron job manipulations can indicate unauthorized persistence attempts or scheduled malicious actions. If confirmed malicious, this activity could lead to system compromise, unauthorized access, or broader network compromise.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
0034
The following analytic detects the use of the 'find' command with 'sudo' and '-exec' options, which can indicate an attempt to escalate privileges on a Linux system. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs that include command-line arguments. This activity is significant because it can allow a user to execute system commands as root, potentially leading to a root shell. If confirmed malicious, this could enable an attacker to gain full control over the system, leading to severe security breaches and unauthorized access to sensitive data.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
0034
The following analytic detects the use of the LD_PRELOAD environment variable to hijack or hook library functions on a Linux platform. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs that include command-line details. This activity is significant because adversaries, malware authors, and red teamers commonly use this technique to gain elevated privileges and establish persistence on a compromised machine. If confirmed malicious, this behavior could allow attackers to execute arbitrary code, escalate privileges, and maintain long-term access to the system.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0034
The analytic identifies potential enumeration of local network configuration on Linux systems. It detects this activity by monitoring processes such as "arp," "ifconfig," "ip," "netstat," "firewall-cmd," "ufw," "iptables," "ss," and "route" within a 30-minute window. This behavior is significant as it often indicates reconnaissance efforts by adversaries to gather network information for subsequent attacks. If confirmed malicious, this activity could enable attackers to map the network, identify vulnerabilities, and plan further exploitation or lateral movement within the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0034
The analytic detects attempts to disable a service on a Linux system. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on processes like "systemctl," "service," and "svcadm" with commands containing "disable." This activity is significant as adversaries may disable security or critical services to evade detection and facilitate further malicious actions, such as deploying destructive payloads. If confirmed malicious, this could lead to the termination of essential security services, allowing attackers to persist undetected and potentially cause significant damage to the system.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1033
The following analytic detects the execution of the 'doas' tool on a Linux host. This tool allows standard users to perform tasks with root privileges, similar to 'sudo'. The detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity is significant as 'doas' can be exploited by adversaries to gain elevated privileges on a compromised host. If confirmed malicious, this could lead to unauthorized administrative access, potentially compromising the entire system.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
0033
The following analytic detects a high frequency of file deletions in the /etc/ folder on Linux systems. It leverages the Endpoint.Filesystem data model to identify instances where 200 or more files are deleted within an hour, grouped by process name and process ID. This behavior is significant as it may indicate the presence of wiper malware, such as AcidRain, which aims to delete critical system files. If confirmed malicious, this activity could lead to severe system instability, data loss, and potential disruption of services.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
1033
The following analytic detects the insertion of a Linux kernel module using the insmod utility. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs that include process names and command-line details. This activity is significant as it may indicate the installation of a rootkit or malicious kernel module, potentially allowing an attacker to gain elevated privileges and bypass security detections. If confirmed malicious, this could lead to unauthorized code execution, persistent access, and severe compromise of the affected system.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
The analytic identifies the use of the 'kmod' process to list kernel modules on a Linux system. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. While listing kernel modules is not inherently malicious, it can be a precursor to loading unauthorized modules using 'insmod'. If confirmed malicious, this activity could allow an attacker to load kernel modules, potentially leading to privilege escalation, persistence, or other malicious actions within the system.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
0033
The following analytic detects the execution of the RPM Package Manager with elevated privileges, specifically when it is used to run system commands as root via the `--eval` and `lua:os.execute` options. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions and process metadata. This activity is significant because it indicates a potential privilege escalation attempt, allowing a user to gain root access. If confirmed malicious, this could lead to full system compromise, unauthorized access to sensitive data, and further exploitation of the environment.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
0033
This analytic detects the creation of the "sudoers.tmp" file, which occurs when editing the /etc/sudoers file using visudo or another editor on a Linux platform. Monitoring this activity is crucial as adversaries may exploit it to gain elevated privileges on a compromised host. If confirmed malicious, this activity could allow attackers to modify sudoers configurations, potentially granting them unauthorized access to execute commands as other users, including root, thereby compromising the system's security.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
0033
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