Detections

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

7,138 detections

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 analytic detects the execution of the 'apt-get' command with elevated privileges using 'sudo' on a Linux system. 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 it indicates a user may be attempting to escalate privileges to root, which could lead to unauthorized system control. If confirmed malicious, an attacker could gain root access, allowing them to execute arbitrary commands, install or remove software, and potentially compromise the entire system.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0039
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 file permissions modifications using the chattr command, which may indicate an attacker attempting to manipulate file attributes to evade detection or prevent alteration. The chattr command can be used to make files immutable or restrict deletion, which can be leveraged to protect malicious files or disrupt system operations. By monitoring for unusual or unauthorized chattr usage, this analytic helps identify potential tampering with critical files, enabling security teams to quickly respond to and mitigate threats associated with unauthorized file attribute changes.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1039
The analytic detects the deletion of service files on a Linux machine within system directories (e.g., /etc/systemd/, /lib/systemd/, /run/systemd/). This activity is significant because attackers may delete or modify services to disable security features, evade defenses, impair system functionality, or execute a destructive payload. Immediate investigation is required to determine the responsible process and user.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0039
The following analytic detects the creation of files in the /etc/profile.d directory on Linux systems. It leverages filesystem data to identify new files in this directory, which is often used by adversaries for persistence by executing scripts upon system boot. This activity is significant as it may indicate an attempt to maintain long-term access to the compromised host. If confirmed malicious, this could allow attackers to execute arbitrary code with elevated privileges each time the system boots, potentially leading to further compromise and data exfiltration.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0039
The following analytic detects attempts to access or dump the contents of /etc/passwd and /etc/shadow files on Linux systems. It leverages data from Linux Auditd, focusing on processes like 'cat', 'nano', 'vim', and 'vi' accessing these files. This activity is significant as it may indicate credential dumping, a technique used by adversaries to gain persistence or escalate privileges. If confirmed malicious, attackers could obtain hashed passwords for offline cracking, leading to unauthorized access and potential system compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0038
This analytic detects the use of the LD_PRELOAD environment variable to hijack or hook library functions on a Linux platform. It leverages data from Linux Auditd, 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
0038
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 the use of the curl command with specific switches (-F, --form, --upload-file, -T, -d, --data, --data-raw, -I, --head) to upload AWS credentials or configuration files to a remote destination. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions and process details. This activity is significant as it may indicate an attempt to exfiltrate sensitive AWS credentials, a technique known to be used by the TeamTNT group. If confirmed malicious, this could lead to unauthorized access and potential compromise of AWS resources.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0038
The analytic detects the execution of a kworker process with a command line in writable directories such as /home/, /var/log, and /tmp on a Linux machine. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process and parent process paths. This activity is significant as kworker processes are typically kernel threads, and their presence in writable directories is unusual and indicative of potential malware, such as CyclopsBlink. If confirmed malicious, this could allow attackers to blend malicious processes with legitimate ones, leading to persistent access and further system compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0038
The analytic detects the execution of the "sudoedit -s *" command, which is associated with the Baron Samedit CVE-2021-3156 heap-based buffer overflow vulnerability. This detection leverages the `osquery_process` data source to identify instances where this specific command is run. This activity is significant because it indicates an attempt to exploit a known vulnerability that allows privilege escalation. If confirmed malicious, an attacker could gain full control of the system, execute arbitrary code, or access sensitive data, leading to potential data breaches and system disruptions.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0037
The analytic detects suspicious Base64 decode operations that may indicate malicious activity, such as data exfiltration or execution of encoded commands. Base64 is commonly used to encode data for safe transmission, but attackers may abuse it to conceal malicious payloads. This detection focuses on identifying unusual or unexpected Base64 decoding processes, particularly when associated with critical files or directories. By monitoring these activities, the analytic helps uncover potential threats, enabling security teams to respond promptly and mitigate risks associated with encoded malware or unauthorized data access.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0037
The following analytic detects the execution of the 'visudo' utility to modify the /etc/sudoers file on a Linux system. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs. This activity is significant because unauthorized changes to the /etc/sudoers file can grant elevated privileges to users, potentially allowing adversaries to execute commands as root. If confirmed malicious, this could lead to full system compromise, privilege escalation, and persistent unauthorized access, severely impacting the security posture of the affected host.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0037
The analytic detects the creation of the /etc/at.allow or /etc/at.deny configuration files in Linux. These files control user permissions for the "at" scheduling application and can be abused by attackers to establish persistence. If confirmed malicious, this could allow unauthorized execution of malicious code, leading to potential data theft or further system compromise. Analysts should review the file path, creation time, and associated processes to assess the threat.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0036
The following analytic detects the execution of the "At" application in Linux, which can be used by attackers to create persistence entries on a compromised host. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and parent process names associated with "at" or "atd". This activity is significant because the "At" application can be exploited to maintain unauthorized access or deliver additional malicious payloads. If confirmed malicious, this behavior could lead to data theft, ransomware attacks, or other severe consequences. Immediate investigation is required to determine the legitimacy of the execution and mitigate potential risks.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
0036
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 following analytic detects the deletion of cron jobs on a Linux machine. It leverages filesystem event logs to identify when files within the "/etc/cron.*" directory are deleted. This activity is significant because attackers or malware may delete cron jobs to disable scheduled security tasks or evade detection mechanisms. If confirmed malicious, this action could allow an attacker to disrupt system operations, evade security measures, or facilitate further malicious activities such as data wiping, as seen with the acidrain malware.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0036
The following analytic detects attempts to escalate privileges on a Linux system using Docker. It identifies processes where Docker commands are used to mount the root directory or execute shell commands within a container. This detection leverages Endpoint Detection and Response (EDR) telemetry, focusing on process names, command-line arguments, and parent processes. This activity is significant because it can allow an attacker with Docker privileges to modify critical system files, such as /etc/passwd, to create a superuser. If confirmed malicious, this could lead to full system compromise and persistent unauthorized access.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0036
The analytic detects the execution of the 'gawk' command with elevated privileges on a Linux system. It identifies command-line executions where 'gawk' is used with 'sudo' and 'BEGIN{system' patterns. This activity indicates a potential privilege escalation attempt, allowing a user to execute system commands as root. If confirmed malicious, this could lead to full root access, enabling the attacker to control the system, modify critical files, and maintain persistent access.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
1036
The analytic detects attempts to access or dump the contents of /etc/passwd and /etc/shadow files on Linux systems. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on processes like 'cat', 'nano', 'vim', and 'vi' accessing these files. This activity is significant as it may indicate credential dumping, a technique used by adversaries to gain persistence or escalate privileges. If confirmed malicious, attackers could obtain hashed passwords for offline cracking, leading to unauthorized access and potential system compromise.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
1036
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