defensive-file-upload

Detect webshell uploads using YARA, Sigma, and KQL queries.

1|Updated Apr 27, 2026
One-click install
npx skills add https://github.com/riparino/Claude-Cyber --skill defensive-file-upload
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: defensive-file-upload
Source: https://github.com/riparino/Claude-Cyber/tree/main/Claude-Blue/Skills/defensive-file-upload
Command: npx skills add https://github.com/riparino/Claude-Cyber --skill defensive-file-upload

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

File upload abuse is a common attack vector against web applications. This skill helps identify malicious uploads and webshell activity by combining YARA signatures, logging analysis, and IOC mapping to enable rapid containment.

Core Features & Use Cases

  • YARA-based webshell detection in upload directories and webroots.
  • Sigma rules for HTTP requests to upload paths and file-creation events.
  • KQL queries for MDE DeviceFileEvents and Web server logs to surface webshell activity.
  • Use Case: SOC teams triage upload abuse incidents and DFIR accelerates investigations.

Quick Start

Inspect upload directories with a YARA scan, correlate with logs to confirm suspicious webshell activity, and begin containment.

Frequently Asked Questions about defensive-file-upload

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I detect webshell uploads in web server logs and file systems?▼

Detect webshell uploads by running YARA scans against upload directories and correlating matches with HTTP requests and file-creation events in logs to confirm malicious activity. This approach surfaces webshells planted via file-upload abuse.

What is the best way to investigate file-upload abuse during incident response?▼

Investigating file-upload abuse involves applying Sigma rules for HTTP requests to upload paths and mapping file-creation events to identify malicious payloads. This accelerates incident response and enables rapid containment of compromised endpoints.

Can I use KQL queries to hunt for webshell activity in MDE and IIS logs?▼

Yes, you can use KQL queries for MDE DeviceFileEvents and IIS log analysis to hunt for webshell activity. These queries surface suspicious file creation and HTTP requests associated with file-upload abuse across web servers.

Does this approach work for SOC triage of suspicious HTTP requests to upload paths?▼

Yes, this approach supports SOC triage by applying Sigma-based monitoring for HTTP requests targeting upload paths. It maps file-creation events and YARA signatures to identify webshell activity for rapid containment.

How do I start a YARA scan for webshell detection in webroots?▼

Start a YARA scan by inspecting upload directories and webroots for webshell signatures. Correlate detected files with web server logs to confirm suspicious activity and begin incident containment.