Implementing File Integrity Monitoring With Aide

Implementing File Integrity Monitoring with AIDE

Overview

AIDE (Advanced Intrusion Detection Environment) is a host-based intrusion detection system that monitors file and directory integrity using cryptographic checksums. This skill covers generating AIDE configuration files, initializing baseline databases, running integrity checks, parsing change reports, and setting up automated cron-based monitoring with alerting.

When to Use

Trigger phrases:

• "implementing file integrity monitoring with aide"

• "Configure AIDE (Advanced Intrusion Detection Environment) for file integrity mon"

• When deploying or configuring implementing file integrity monitoring with aide capabilities in your environment

• When establishing security controls aligned to compliance requirements

• When building or improving security architecture for this domain

• When conducting security assessments that require this implementation

Prerequisites

• AIDE installed on target Linux system (apt install aide / yum install aide)
• Root or sudo access for file system scanning
• Python 3.8+ with standard library

Steps

# Example: IOC detection
import re

IOC_PATTERNS = {
    "ip": r"\b(?:\d{1,3}\.){3}\d{1,3}\b",
    "domain": r"\b[a-z0-9-]+\.[a-z]{2,}\b",
    "hash_md5": r"\b[a-f0-9]{32}\b",
    "hash_sha256": r"\b[a-f0-9]{64}\b",
}

def extract_iocs(text: str) -> dict:
    return {k: re.findall(v, text) for k, v in IOC_PATTERNS.items()}

1. Generate AIDE Configuration — Create aide.conf with monitoring rules for critical directories (/etc, /bin, /sbin, /usr/bin, /boot)
2. Initialize Baseline Database — Run aide --init to create the initial file integrity baseline
3. Run Integrity Check — Execute aide --check to compare current state against baseline
4. Parse Change Report — Extract added, removed, and changed files from AIDE output
5. Configure Automated Monitoring — Generate cron job for scheduled integrity checks
6. Generate Compliance Report — Produce structured report of all file changes with severity classification

Expected Output

• AIDE configuration file (aide.conf)
• Baseline database creation status
• JSON report of file changes (added/removed/changed) with severity
• Cron job configuration for automated monitoring

When NOT to Use

• You need to test the implementation (use performing-* skills)
• Task is about configuring existing tools (use configuring-* skills)
• You need to analyze security events (use analyzing-* skills)
• Task is about building detection rules (use building-* skills)
• You don't have access to the target environment
• Task requires vendor-specific expertise (consult vendor docs)

Red Flags

• Performing actions without explicit written authorization from the asset owner
• Testing against production systems without a defined scope and rules of engagement
• Acting on threat intelligence without validating source reliability
• Sharing classified or sensitive indicators without proper handling procedures
• Alerting threat actors to detection capabilities through visible response actions

Process

1. Plan — Define infrastructure requirements, security constraints, rollback strategy
2. Implement — Configure resources, apply security best practices, test in staging
3. Deploy & Monitor — Roll out to production, verify health checks, set up alerting

Verification

• All steps executed successfully against a test environment before production use
• Output documented with screenshots or logs demonstrating expected behavior
• Results validated against known-good baselines or reference implementations
• Documentation complete enough for another analyst to reproduce findings

Anti-Rationalization Table