Apache HTTP Server

Attackers compromise web servers (Apache, Nginx, Tomcat, PHP) and leverage them to make unexpected outbound network connections to public file-sharing or content hosting services, indicating post-exploitation activity for ingress tool transfer and further compromise.

This brief details how attackers exploit Local File Inclusion (LFI) vulnerabilities on web servers such as Nginx, Apache, IIS, and Traefik, by using directory traversal or direct sensitive file path requests to disclose system information, credentials, and configuration files, potentially leading to remote code execution and system compromise.

This detection rule identifies suspicious child process executions originating from web server processes on Linux systems, indicating that attackers may have exploited web application vulnerabilities such as command injection or remote file inclusion to establish persistence or execute malicious commands.

This brief details how attackers exploit vulnerable web applications or deploy webshells on Linux systems to achieve persistence by executing unusual shell commands from web server processes, potentially leading to payload downloads, reverse shells, or cron-like task implants.

This brief describes how attackers exploit vulnerabilities in web applications to execute suspicious shell commands via web server processes on Linux, enabling persistence, discovery, credential access, and reverse shell establishment, which can lead to full system compromise and data exfiltration.

Attackers are actively exploiting Server-Side Request Forgery (SSRF) vulnerabilities in public-facing web applications to access cloud instance metadata services, such as those on AWS, GCP, and Azure, to harvest temporary credentials and sensitive instance details.

The new_terms rule detects potential HTTP downgrade attacks by identifying HTTP traffic using a different HTTP version than typically used, potentially exposing systems to vulnerabilities in older protocols.

An unusual spike in web server error codes (500, 502, 503, 504) may indicate reconnaissance activities like vulnerability scanning or fuzzing, where attackers probe for weaknesses, potentially leading to exploitation of server-side issues.

This brief focuses on detecting malicious activity related to web shells on Windows systems by identifying the execution of command interpreters and scripting engines as child processes of common web server processes, potentially indicating unauthorized command execution and persistent access.

This rule detects potential Remote File Inclusion (RFI) activity on web servers by identifying HTTP GET requests that attempt to access sensitive remote files through directory traversal techniques or known file paths, potentially leading to information disclosure or further compromise.

This rule detects potential Remote File Inclusion (RFI) activity on web servers by identifying HTTP GET requests that attempt to access sensitive remote files through directory traversal techniques or known file paths to read sensitive files, gain system information, or further compromise the server.

This rule detects potential web server discovery or fuzzing activity by identifying a high volume of HTTP GET requests resulting in 404 or 403 status codes from a single source IP address within a short timeframe, indicating attackers discovering hidden resources for targeted attacks.

The rule detects potential command injection attempts via web server requests by identifying URLs that contain suspicious patterns commonly associated with command execution payloads.

Detection of unusual spikes in web server requests with uncommon or suspicious user-agent strings indicative of reconnaissance attempts to identify web application vulnerabilities or brute-force attacks.

Detection of web server discovery or fuzzing activity indicated by a high volume of HTTP GET requests resulting in 404 or 403 status codes originating from a single source IP address within a short timeframe, suggesting attempts to discover hidden resources.

Detection of potential web server discovery or fuzzing activity characterized by a high volume of HTTP GET requests resulting in 404 or 403 status codes originating from a single source IP address within a short timeframe, indicating attackers are probing for hidden resources.