Hancock: A Cybersecurity Automation Platform Based on Domain-Specific Large Language Models

This article introduces the open-source Hancock project, a tool that leverages domain-specific large language models to automate cybersecurity tasks, covering core security scenarios such as penetration testing, threat detection, and Security Operations Center (SOC) analysis.

Cybersecurity has always been one of the most challenging areas in the tech field. The continuous evolution of attack methods, the explosive growth of threat intelligence, and the persistent shortage of security analysts have put enormous pressure on traditional security operation models. The emergence of large language models has brought new possibilities to this field.

The Hancock project explores a specific direction: using specially trained and optimized domain-specific large language models for cybersecurity to automate tasks such as penetration testing, threat detection, and Security Operations Center (SOC) analysis. This 'AI + Security' integration may be redefining the future of cybersecurity work.

Modern enterprises' security operations face multiple challenges:

Talent Shortage: The global cybersecurity talent gap continues to widen, with experienced security analysts in short supply.

Data Overload: SIEM systems generate massive amounts of alerts daily; analysts are overwhelmed, and real threats are often buried in noise.

Response Delay: The time window from threat detection to effective response is getting shorter, and traditional manual analysis processes can hardly meet the demand.

Skill Threshold: Tasks like penetration testing and vulnerability analysis require deep professional knowledge and have a long training cycle.

Large language models show unique advantages in the following aspects:

• Pattern Recognition: Identify abnormal patterns and attack signatures from massive logs
• Knowledge Integration: Correlate and analyze scattered threat intelligence, vulnerability information, and best practices
• Natural Language Understanding: Parse unstructured data such as security reports, vulnerability descriptions, and attack reproduction documents
• Code Analysis: Review security vulnerabilities in code and generate exploit code or repair suggestions

The Hancock project, based on these potentials, has built a set of practical security automation tools.

Hancock's penetration testing module aims to assist security testers rather than completely replace humans. Its main functions include:

Reconnaissance and Information Gathering:

• Automate subdomain enumeration, port scanning, and service identification
• Use LLMs to analyze collected information and identify potential attack surfaces
• Generate structured reconnaissance reports and mark high-risk targets

Vulnerability Analysis and Exploitation:

• Analyze the target system's tech stack and match against known vulnerability databases
• Generate targeted test payloads based on vulnerability descriptions
• Explain vulnerability principles and potential impacts to assist testers in decision-making

Report Generation:

• Automatically organize findings from the testing process
• Generate penetration testing reports compliant with industry standards (e.g., OWASP)
• Provide repair suggestions and priority ranking

In terms of threat detection, Hancock focuses on enhancing analysts' capabilities:

Alert Enrichment and Classification:

• Receive raw alerts from SIEM systems
• Use LLMs for contextual analysis, correlating related logs and threat intelligence
• Prioritize alerts and mark high-risk events that require human intervention

Threat Hunting Assistance:

• Hypothesis-driven threat hunting methodology
• Automatically generate hunting query statements (e.g., Splunk SPL, KQL)
• Analyze hunting results and identify potential APT activity traces

IOC Extraction and Sharing:

• Extract Indicators of Compromise (IOCs) from threat reports and sandbox analysis results
• Standardize IOC formats for easy integration with threat intelligence platforms
• Generate structured threat intelligence reports

The Security Operations Center (SOC) is a key application scenario for Hancock:

Preliminary Incident Analysis:

• Automatically collect all contextual information related to alerts
• Perform preliminary causal analysis to determine if it is a real threat
• Automatically generate closure suggestions for obvious false positives

Response Playbook Generation:

• Recommend standard response processes based on incident types
• Generate executable automation scripts (e.g., isolate affected hosts, block malicious IPs)
• Track response execution status to ensure a closed-loop handling process

Knowledge Base Maintenance:

• Extract lessons learned from handled security incidents
• Automatically update internal knowledge bases and detection rules
• Support natural language queries to help analysts quickly find historical cases

The key difference between Hancock and general LLM applications lies in its domain-specific model strategy. The project adopts the following technical approaches:

Domain Fine-Tuning: Based on open-source foundation models (e.g., Llama, Mistral), fine-tuned using cybersecurity domain data. Training data includes:

• CVE vulnerability descriptions and PoC code
• Penetration testing reports and methodology documents
• Threat intelligence reports (e.g., public reports from Mandiant, FireEye)
• Security tool documents and user manuals
• Malware analysis reports

Retrieval-Augmented Generation (RAG):

• Build a security knowledge vector database containing the latest vulnerability information, threat intelligence, and tool documents
• When generating responses, first retrieve relevant knowledge, then combine with model capabilities to generate answers
• Ensure the timeliness and accuracy of output content

Multi-Agent Collaboration:

• Design multiple dedicated agents, each responsible for different tasks such as reconnaissance, analysis, exploitation, and reporting
• Agents collaborate via structured messages
• Simulate the workflow of a real penetration testing team