EXPLORE DETECTIONS
Linux Ghostscript Exploitation
The following analytic detects exploitation of Ghostscript causing command execution. This can be used by attackers to abuse file conversion services or embedded LibreOffice documents.
Linux GNU Awk Privilege Escalation
The following analytic detects the execution of the 'gawk' command with elevated privileges on a Linux system. It leverages Endpoint Detection and Response (EDR) telemetry to identify command-line executions where 'gawk' is used with 'sudo' and 'BEGIN{system' patterns. This activity is significant because it 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.
Linux Hardware Addition SwapOff
The following analytic detects the execution of the "swapoff" command, which disables the swapping of paging devices on a Linux system. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs. 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.
Linux High Frequency Of File Deletion In Boot Folder
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.
Linux High Frequency Of File Deletion In Etc Folder
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.
Linux Impair Defenses Process Kill
The following analytic identifies the execution of the 'pkill' command, which is used to terminate processes on a Linux system. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity is significant because threat actors often use 'pkill' to disable security defenses or terminate critical processes, facilitating further malicious actions. If confirmed malicious, this behavior could lead to the disruption of security applications, enabling attackers to evade detection and potentially corrupt or destroy files on the targeted system.
Linux Indicator Removal Clear Cache
The following analytic detects processes that clear or free page cache on a Linux system. It leverages Endpoint Detection and Response (EDR) data, focusing on specific command-line executions involving the kernel system request `drop_caches`. This activity is significant as it may indicate an attempt to delete forensic evidence or the presence of wiper malware like Awfulshred. If confirmed malicious, this behavior could allow an attacker to cover their tracks, making it difficult to investigate other malicious activities or system compromises.
Linux Indicator Removal Service File Deletion
The following analytic detects the deletion of Linux service unit configuration files by suspicious processes. It leverages Endpoint Detection and Response (EDR) telemetry, focusing on processes executing the 'rm' command targeting '.service' files. This activity is significant as it may indicate malware attempting to disable critical services or security products, a common defense evasion tactic. If confirmed malicious, this behavior could lead to service disruption, security tool incapacitation, or complete system compromise, severely impacting the integrity and availability of the affected Linux host.
Linux Ingress Tool Transfer Hunting
The following analytic detects the use of 'curl' and 'wget' commands within a Linux environment. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names, user information, and command-line executions. This activity is significant as 'curl' and 'wget' are commonly used for downloading files, which can indicate potential ingress of malicious tools. If confirmed malicious, this activity could lead to unauthorized code execution, data exfiltration, or further compromise of the system. Monitoring and tuning this detection helps identify and differentiate between normal and potentially harmful usage.
Linux Ingress Tool Transfer with Curl
The following analytic detects the use of the curl command with specific switches (-O, -sO, -ksO, --output) commonly used to download remote scripts or binaries. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line arguments. This activity is significant as it may indicate an attempt to download and execute potentially malicious files, often used in initial stages of an attack. If confirmed malicious, this could lead to unauthorized code execution, enabling attackers to compromise the system further.
Linux Insert Kernel Module Using Insmod Utility
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.
Linux Install Kernel Module Using Modprobe Utility
The following analytic detects the installation of a Linux kernel module using the modprobe utility. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity is significant because installing a kernel module can indicate an attempt to deploy a rootkit or other malicious kernel-level code, potentially leading to elevated privileges and bypassing security detections. If confirmed malicious, this could allow an attacker to gain persistent, high-level access to the system, compromising its integrity and security.
Linux Iptables Firewall Modification
The following 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.
Linux Kernel Module Enumeration
The following 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.
Linux Kworker Process In Writable Process Path
The following 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.
Linux Magic SysRq Key Abuse
Detects potential abuse of the Linux Magic SysRq (System Request) key by adversaries with root or sufficient privileges to manipulate or destabilize a system. Writing to /proc/sysrq-trigger can crash the system, kill processes, or bypass standard logging. Monitoring SysRq abuse helps detect stealthy post-exploitation activity. Correlate with related EXECVE or PROCTITLE events to identify the process or user responsible for the access or modification.
Linux Make Privilege Escalation
The following analytic detects the use of the 'make' command with elevated privileges to execute system commands as root, potentially leading to a root shell. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions that include 'make', '--eval', and 'sudo'. This activity is significant because it indicates a possible privilege escalation attempt, allowing a user to gain root access. If confirmed malicious, an attacker could achieve full control over the system, execute arbitrary commands, and compromise the entire environment.
Linux Malformed Auth Entry
The following analytic detects when su runs from a page-cache-corrupted binary. When this happens a partial corruption of its runtime state can prevent it from resolving the identity of the calling user. Under normal conditions, su logs both the target account and the invoking user. When exploitation has occurred via this path, the invoking username field is absent. This activity is significant because it indicates a possible privilege escalation attempt, allowing a user to gain root access. If confirmed malicious, an attacker could achieve full control over the system, execute arbitrary commands, and compromise the entire environment.
Linux Medusa Rootkit
This detection identifies file creation events associated with the installation of the Medusa rootkit, a userland LD_PRELOAD-based rootkit known for deploying shared objects, loader binaries, and configuration files into specific system directories. These files typically facilitate process hiding, credential theft, and backdoor access. Monitoring for such file creation patterns enables early detection of rootkit deployment before full compromise.
Linux MOTD Script Added
The following analytic detects the creation of a file within the /etc/update-motd.d directory. This is used to add scripts that run with Message of the Day (MOTD) when a user logs in. This can be used by attackers for persistence if it contains malicious code.
Linux MySQL Privilege Escalation
The following analytic detects the execution of MySQL commands with elevated privileges using sudo, which can lead to privilege escalation. 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 potential misuse of MySQL to execute system commands as root, which could allow an attacker to gain root shell access. If confirmed malicious, this could result in full control over the affected system, leading to severe security breaches and unauthorized access to sensitive data.
Linux Netcat Outbound Connection
The following analytic detects outbound network connections originating from Netcat or Netcat-like binaries on Linux systems. Netcat is a versatile networking utility that, while legitimate in some contexts, is frequently abused by attackers to establish reverse shells, exfiltrate data, or create persistent backdoor connections to remote systems. This activity is significant because outbound connections from these binaries often indicate an active compromise, where an attacker may be maintaining command-and-control communication or tunneling malicious traffic. If confirmed malicious, this could lead to unauthorized data exfiltration, lateral movement, or persistent remote access to the compromised system.
Linux Ngrok Reverse Proxy Usage
The following analytic detects the use of Ngrok on a Linux operating system. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line arguments associated with Ngrok. This activity is significant because Ngrok 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.
Linux Node Privilege Escalation
The following analytic identifies the execution of Node.js with elevated privileges using sudo, specifically when spawning child processes. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions that include specific Node.js commands. This activity is significant because 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.