Browse Rules

Binfmt Configuration File Creation

This rule detects the creation of a binfmt configuration file. Binfmt is a utility that is used to configure the behavior of the Linux kernel when executing binary files. By creating a malicious binfmt configuration file, threat actors can execute a backdoor script or command on the target system.

File Downloaded by Curl/Wget and Piped to Interpreter

This rule detects when a file is downloaded by curl or wget, and piped to an interpreter. Attackers may use this technique to download and execute payloads for various malicious purposes, such as establishing persistence or exfiltrating data.

Process Execution Followed by Self-Deletion

Detects a process execution followed by immediate self-deletion, a common technique used by adversaries to remove traces of their activity on the system. This pattern is often observed in malware and APT campaigns.

Suspicious Reading of procfs Syscall File

This rule detects command lines that reference another process or thread's procfs syscall file. The "/proc/<pid>/syscall" interface exposes the current syscall arguments, stack pointer, and instruction pointer, which can support process discovery and preparation for process injection. Self and thread-self aliases are excluded.

Suspicious Java Class File Created in PaperCut Server Library

Detects creation of Java .class files within the PaperCut NG/MF Application Server library directory. During active exploitation of CVE-2026-82078 (chained with CVE-2026-81578), attackers deliver hex-encoded malicious .class payloads into the PaperCut server/lib path (observed examples include Udydn.class and Moo97.class) so arbitrary bytecode executes inside the PaperCut JVM / Application Server process.

Potential Privilege Escalation via SUID/SGID

Detects potential privilege escalation under the root effective user when the real user and parent user are not root, indicative of the execution of binaries with SUID or SGID bits set.

Potential Java Service Exploitation via Suspicious Child Process

Identifies a Java process that accepts an inbound network connection and then spawns a suspicious child process. This may indicate exploitation of a Java service that runs attacker-controlled code, such as one that deserializes untrusted objects.

Potential Privilege Escalation via unshare and UID Change

Identifies potentially suspicious use of unshare to create a user namespace context followed by a UID change event indicating a transition to root. Adversaries may use unshare-based primitives as part of local privilege escalation chains. This rule is intentionally generic and can surface multiple local privesc patterns beyond a single CVE.

Sensitive Files Compression

Identifies the use of a compression utility to collect known files containing sensitive information, such as credentials and system configurations.

Suspicious /proc/maps Discovery

Monitors for /proc/*/maps file reads. The /proc/*/maps file in Linux provides a memory map for a specific process, detailing the memory segments, permissions, and what files are mapped to these segments. Attackers may read a process's memory map to identify memory addresses for code injection or process hijacking.

Linux Clipboard Activity Detected

This rule monitors for the usage of the most common clipboard utilities on unix systems by an uncommon process parent. Adversaries may collect data stored in the clipboard from users copying information within or between applications.

Suspicious Process Execution by Zoom

Identifies suspicious process execution associated with the Zoom desktop client on macOS and Linux. The rule detects shells, script interpreters, downloaders, and network utilities spawned by Zoom on either platform. On Linux, it also detects Zoom replacing its own process image with an executable outside the Zoom installation directory. These behaviors may indicate successful exploitation of a Zoom client vulnerability, including CVE-2026-53413.

Unusual File Creation via Web Server

This rule leverages the "new_terms" rule type to detect unusual file creations originating from web server processes on Linux systems. Attackers may exploit web servers to maintain persistence on a compromised system, often resulting in atypical file creations. As file creations from web server processes are common, the "new_terms" rule type approach helps to identify deviations from normal behavior.

Elastic Agent Service Terminated

Identifies the Elastic endpoint agent has stopped and is no longer running on the host. Adversaries may attempt to disable security monitoring tools in an attempt to evade detection or prevention capabilities during an intrusion. This may also indicate an issue with the agent itself and should be addressed to ensure defensive measures are back in a stable state.

GenAI or MCP Server Child Process Execution

Detects child process execution from GenAI tools or MCP (Model Context Protocol) servers. Adversaries exploit AI agents to execute system commands, exfiltrate data, or establish persistence. MCP servers provide LLMs direct access to execute shell commands, read files, and interact with external services. This building block provides visibility into AI-initiated process execution for correlation with other suspicious activity.

LLM-Based Curl Activity Triage via Auditd

Detects non-allowlisted curl activity on Linux hosts via Auditd Manager or Auditbeat and uses an LLM to assess whether the activity is malicious, benign, or requires investigation. The rule parses and normalizes the destination, redacts sensitive command-line values, and aggregates activity by host and destination before invoking the ES|QL COMPLETION command. Only true positive or suspicious verdicts with confidence above 0.7 generate alerts.

LLM-Based Curl Activity Triage

Detects non-allowlisted curl activity on Linux, macOS, and Windows hosts and uses an LLM to assess whether the activity is malicious, benign, or requires investigation. The rule parses and normalizes the destination, redacts sensitive command-line values, and aggregates activity by host and destination before invoking the ES|QL COMPLETION command. Only true positive or suspicious verdicts with confidence above 0.7 generate alerts.

LLM-Based Wget Activity Triage via Auditd

Detects non-allowlisted wget activity on Linux hosts via Auditd Manager or Auditbeat and uses an LLM to assess whether the activity is malicious, benign, or requires investigation. The rule parses and normalizes the destination, redacts sensitive command-line values, and aggregates activity by host and destination before invoking the ES|QL COMPLETION command. Only true positive or suspicious verdicts with confidence above 0.7 generate alerts.

LLM-Based Wget Activity Triage

Detects non-allowlisted wget activity on Linux, macOS, and Windows hosts and uses an LLM to assess whether the activity is malicious, benign, or requires investigation. The rule parses and normalizes the destination, redacts sensitive command-line values, and aggregates activity by host and destination before invoking the ES|QL COMPLETION command. Only true positive or suspicious verdicts with confidence above 0.7 generate alerts.

Kernel Module Loaded with Tainting Flags

This rule detects the loading of tainted kernel modules on Linux systems. A tainted kernel module indicates that the module is not officially supported or may have been modified. Attackers may load tainted kernel modules to maintain persistence or evade detection on the system. This may be a sign of malicious activity involving kernel modules.

Direct Process Execution via Background Utility

This is a New Terms rule that identifies the first occurrence of setsid or nohup being used to directly execute a process on a host. Attackers may leverage these tools to execute commands in a new session and/or to ignore signals.

PHP File Creation in WordPress Plugin Directory

Detects the creation of a PHP file in the WordPress plugin directory, which is a common technique used by attackers to establish persistence on a compromised web server. Attackers may upload a malicious PHP file and call it from a web browser to gain remote access to the server.

Potential CVE-2025-41244 vmtoolsd LPE Exploitation Attempt

This rule looks for processes that behave like an attacker trying to exploit a known vulnerability in VMware tools (CVE-2025-41244). The vulnerable behavior involves the VMware tools service or its discovery scripts executing other programs to probe their version strings. An attacker can place a malicious program in a writable location (for example /tmp) and have the tools execute it with elevated privileges, resulting in local privilege escalation. The rule flags launches where vmtoolsd or the

Potential Tunneling via Tailscaled

Identifies the use of Tailscaled to potentially tunnel network traffic. This can be used by attackers to enable routing of network packets that would otherwise not reach their intended destination, or to bypass network restrictions and/or hide traffic from network monitoring.

Suspicious UID Change to Root via Python

Detects a UID change event to 0 (root) where the responsible process is a Python interpreter running from a user- or world-writable working directory and the parent process is non-root. This may be indicative of a local privilege escalation exploit executed via Python. Using the new terms feature, noise from automated tools or system processes is partially filtered out.