Detections

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

1,052 detections

The following analytic detects `spoolsv.exe` writing a `.dll` file, which is unusual behavior and may indicate exploitation of vulnerabilities like CVE-2021-34527 (PrintNightmare). This detection leverages Sysmon EventID 11 to monitor file creation events in the `\spool\drivers\x64\` directory. This activity is significant because `spoolsv.exe` typically does not write DLL files, and such behavior could signify an ongoing attack. If confirmed malicious, this could allow an attacker to execute arbitrary code, escalate privileges, or maintain persistence on the compromised system.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0055
The following analytic detects a suspicious registry modification aimed at disabling security audit logs by adding a specific registry entry. It leverages data from the Endpoint.Registry data model, focusing on changes to the "Control\\MiniNt" registry path. This activity is significant because it can prevent Windows from logging any events to the Security Log, effectively blinding security monitoring efforts. If confirmed malicious, this technique could allow an attacker to operate undetected, making it difficult to trace their actions and compromising the integrity of security audits.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0054
The analytic detects the use of the `curl` command with proxy-related arguments such as `-x`, `socks`, `--preproxy`, and `--proxy`. This activity is significant as it may indicate an adversary attempting to use a proxy to evade network monitoring and obscure their actions. If confirmed malicious, this behavior could allow attackers to bypass security controls, making it difficult to track their activities and potentially leading to unauthorized data access or exfiltration.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0053
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
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 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
This analytic identifies a heap-based buffer overflow in sudoedit by detecting Linux logs containing both "sudoedit" and "segfault" terms. This detection leverages Splunk to monitor for more than five occurrences of these terms on a single host within a specified timeframe. This activity is significant because exploiting this vulnerability (CVE-2021-3156) can allow attackers to gain root privileges, leading to potential system compromise, unauthorized access, and data breaches. If confirmed malicious, this could result in elevated privileges and full control over the affected system, posing a severe security risk.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0041
The following analytic detects potential access or modification of the /etc/sudoers file on a Linux system. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on processes like "cat," "nano," "vim," and "vi" accessing the /etc/sudoers file. This activity is significant because the sudoers file controls user permissions for executing commands with elevated privileges. If confirmed malicious, an attacker could gain persistence or escalate privileges, compromising the security of the targeted host.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0041
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 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
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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 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
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Splunk Security Content
1 year ago
1036
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
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Splunk Security Content
1 year ago
0035
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 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 following analytic identifies DNS requests with unusually large query lengths for the record type being requested. It leverages the Network_Resolution data model and applies a machine learning model to detect outliers in DNS query lengths. This activity is significant because unusually large DNS queries can indicate data exfiltration or command-and-control communication attempts. If confirmed malicious, this activity could allow attackers to exfiltrate sensitive data or maintain persistent communication channels with compromised systems.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0034
The analytic detects the use of the Linux 'xclip' command to copy data from the clipboard. It leverages Endpoint Detection and Response (EDR) 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
1032
The following analytic detects the use of the 'dd' command to overwrite files 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 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
0032
The following analytic detects potential tampering with cronjob files on a Linux system by identifying 'echo' commands that append code to existing cronjob files. It leverages logs from Endpoint Detection and Response (EDR) agents, focusing on process names, parent processes, and command-line executions. This activity is significant because adversaries often use it for persistence or privilege escalation. If confirmed malicious, this could allow attackers to execute unauthorized code automatically, leading to system compromises and unauthorized data access, thereby impacting business operations and data integrity.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0030
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