Detections

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

2,285 detections

This query is looking for rarely seen processes which are launched as a service.
Author: Jouni Mikkola
More info: https://threathunt.blog/rare-process-launch-as-a-service/
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
2014
The analytic detects potential access or modification of the /etc/sudoers file on a Linux system. It leverages data from Linux Auditd, 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
0045
The analytic detects suspicious access or modification of the sshd_config file on Linux systems. It leverages data from Linux Auditd, focusing on command-line executions involving processes like "cat," "nano," "vim," and "vi" accessing the sshd_config file. This activity is significant because unauthorized changes to sshd_config can allow threat actors to redirect port connections or use unauthorized keys, potentially compromising the system. If confirmed malicious, this could lead to unauthorized access, privilege escalation, or persistent backdoor access, posing a severe security risk.
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 Linux Auditd, 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
0031
The following analytic detects suspicious preload hijacking via the `preload` file, which may indicate an attacker's attempt to intercept or manipulate library loading processes. The `preload` file can be used to force the loading of specific libraries before others, potentially allowing malicious code to execute or alter application behavior. By monitoring for unusual or unauthorized modifications to the `preload` file, this analytic helps identify attempts to hijack preload mechanisms, enabling security teams to investigate and address potential threats to system integrity and security.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0028
This rule detects attempts to create or rename files with a space at the end of their filename, which can be used to obfuscate malicious files or commands. Specifically, it looks for command-line executions involving 'echo "*" > * && chmod +x *' or 'mv * "* "'. The first pattern suggests creating an executable file with a trailing space, and the second suggests renaming a file to include a trailing space.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0020
Detects the potential abuse of the Linux Magic SysRq (System Request) key by adversaries with root or sufficient privileges to silently manipulate or destabilize a system. By writing to /proc/sysrq-trigger, they can crash the system, kill processes, or disrupt forensic analysis—all while bypassing standard logging. Though intended for recovery and debugging, SysRq can be misused as a stealthy post-exploitation tool. It is controlled via /proc/sys/kernel/sysrq or permanently through /etc/sysctl.conf.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
2025
The following analytic detects the creation of files typically associated with SharpHound, a reconnaissance tool used for gathering domain and trust data. It leverages file modification events from the Endpoint.Filesystem data model, focusing on default file naming patterns like `*_BloodHound.zip` and various JSON files. This activity is significant as it indicates potential domain enumeration, which is a precursor to more targeted attacks. If confirmed malicious, an attacker could gain detailed insights into the domain structure, facilitating lateral movement and privilege escalation.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1082
The following analytic detects the usage of the `plutil` command to modify plist files on macOS systems. It leverages osquery to monitor process events, specifically looking for executions of `/usr/bin/plutil`. This activity is significant because adversaries can use `plutil` to alter plist files, potentially adding malicious binaries or command-line arguments that execute upon user logon or system startup. If confirmed malicious, this could allow attackers to achieve persistence, execute arbitrary code, or escalate privileges, posing a significant threat to the system's security.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1059
The analytic detects the creation of specific AzureHound-related files, such as `*-azurecollection.zip` and various `.json` files, on disk. It leverages data from the Endpoint.Filesystem datamodel, focusing on file creation events with specific filenames. This activity is significant because AzureHound is a tool used to gather information about Azure environments, similar to SharpHound for on-premises Active Directory. If confirmed malicious, this activity could indicate an attacker is collecting sensitive Azure environment data, potentially leading to further exploitation or privilege escalation within the cloud infrastructure.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0055
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
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
The following analytic detects the addition of NOPASSWD entries to the /etc/sudoers file on Linux systems. It leverages Endpoint Detection and Response (EDR) telemetry 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
0040
The analytic detects modifications to Windows accessibility binaries such as sethc.exe, utilman.exe, osk.exe, Magnify.exe, Narrator.exe, DisplaySwitch.exe, and AtBroker.exe. It leverages filesystem activity data to identify changes to these specific files. This activity is significant because adversaries can exploit these binaries to gain unauthorized access or execute commands without logging in. If confirmed malicious, this could allow attackers to bypass authentication mechanisms, potentially leading to unauthorized system access and further compromise of the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1040
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 analytic identifies modifications to the TranscodedWallpaper file in the wallpaper theme directory, excluding changes made by explorer.exe. This detection leverages the Endpoint.Processes and Endpoint.Filesystem data models to correlate process activity with file modifications. This activity is significant as it may indicate an adversary attempting to deface or change the desktop wallpaper of a targeted host, a tactic often used to signal compromise or deliver a message. If confirmed malicious, this could be a sign of unauthorized access and tampering, potentially leading to further system compromise or data exfiltration.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0039
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 following analytic detects the copying of Chrome's Local State and Login Data files into temporary folders, a tactic often used by the Braodo stealer malware. These files contain encrypted user credentials, including saved passwords and login session details. The detection monitors for suspicious copying activity involving these specific Chrome files, particularly in temp directories where malware typically processes the stolen data. Identifying this behavior enables security teams to act quickly, preventing attackers from decrypting and exfiltrating sensitive browser credentials and mitigating the risk of unauthorized access.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2037
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 analytic detects suspicious command lines that append user entries to `/etc/at.allow` or `/etc/at.deny` files on Linux systems. This activity is significant because altering these configuration files can allow attackers to schedule tasks with elevated permissions, facilitating persistence on a compromised Linux host. If confirmed malicious, this could enable attackers to execute arbitrary code at scheduled intervals, potentially leading to further system compromise and unauthorized access to sensitive information. The rule specifically looks for `echo` commands writing to these files.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0031
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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