| name | implementing-file-integrity-monitoring-with-aide |
| description | Configure AIDE (Advanced Intrusion Detection Environment) for file integrity monitoring including baseline creation, scheduled integrity checks, change detection, and alerting |
| domain | cybersecurity |
| subdomain | endpoint-security |
| tags | ["aide","file-integrity","hids","baseline","intrusion-detection","compliance","linux-security"] |
| version | 1.0 |
| author | mahipal |
| license | Apache-2.0 |
| nist_csf | ["PR.PS-01","PR.PS-02","DE.CM-01","PR.IR-01"] |
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
- 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
Common Misconfigurations & Verification
- Baseline DB stored on the host: if
aide.db.gz lives at its default /var/lib/aide/aide.db.gz on the monitored system, an attacker with root simply re-runs aide --init and copies aide.db.new.gz over it, erasing evidence. Store the baseline (and aide.conf) read-only off-host or on signed/immutable media, and compare against that copy.
- DB never updated after legit changes: after patching, admins run
aide --update and blindly promote aide.db.new.gz to the baseline, masking any malicious change made in the same window. Diff the report before promoting, and update the DB out-of-band.
- Weak rule selection: lines using
p+i only (perms/inode) miss content tampering. Confirm critical paths use a hashing ruleset (e.g., Checksums = sha256+sha512) and that /etc, /bin, /sbin, /usr/bin, /boot are actually in scope and not shadowed by a later !exclude.
- Check not scheduled / output unread: a cron job that writes to a local file no one reads is not monitoring. Verify the cron entry exists and routes results to a SIEM or mailbox.
- Verification: touch a canary change (
chmod o+w /etc/passwd or add a file under /usr/bin), run aide --check, and confirm it reports the added/changed entry with a checksum mismatch; then revert. A clean report after a known change means the rules or DB path are wrong.
Prerequisites
