Lynis Security Scan

Deploy the Lynis system audit tool across all servers. Nightly runs at 3 AM. Silent when no new warnings appear. Alerts if new findings emerge.

Installation

apt-get install -y lynis
lynis --version  # should be 3.1.x+

First Run

lynis audit system --quick

Key output: Hardening index (0-100), Warnings count, Suggestions count.

Results are stored in /var/log/lynis-report.dat and /var/log/lynis.log.

Cron Deployment

The script at /root/.hermes/scripts/lynis-scan.sh:

#!/bin/bash
# Nightly security audit via Lynis
# Runs at 3 AM, outputs report, only alerts on new warnings
LOG="/var/log/lynis-report.dat"
PREV="/root/.hermes/lynis-prev.dat"

lynis audit system --quick > /dev/null 2>&1

# Count warnings
WARNS=$(grep -c "^warning\[\]" "$LOG" 2>/dev/null || echo 0)

# Compare with previous run
if [ -f "$PREV" ]; then
    OLD_WARNS=$(grep -c "^warning\[\]" "$PREV" 2>/dev/null || echo 0)
else
    OLD_WARNS=0
fi

cp "$LOG" "$PREV"

# Only output if something changed
if [ "$WARNS" -ne "$OLD_WARNS" ]; then
    echo "Lynis: $WARNS warnings (was $OLD_WARNS)"
    grep "^warning\[\]" "$LOG" | sed 's/warning\[\]=//' | tr '|' ' '
else
    echo "[SILENT]"
fi

Add as no_agent=True cron:

cronjob(action='create', name='lynis-scan', schedule='0 3 * * *',
  script='lynis-scan.sh', no_agent=True, deliver='origin')

Multi-Server Deployment

Copy the script to each server and add to crontab. Use the server's native crontab rather than the Hermes cron system — the Hermes cron scheduler only runs on the host box, so it cannot schedule jobs on remote servers. Use SSH + crontab -l to deploy remotely:

scp /root/.hermes/scripts/lynis-scan.sh root@<server>:/usr/local/bin/
ssh root@<server> 'chmod +x /usr/local/bin/lynis-scan.sh && \
  (crontab -l 2>/dev/null; echo "0 3 * * * /usr/local/bin/lynis-scan.sh") | crontab -'

Servers deployed

Server	IP	Date deployed	Status
Core (netcup)	152.53.192.33	Jul 6, 2026	✅ Running via cron job
wphost02 (Hetzner)	5.161.62.38	Jul 7, 2026	✅ Running via crontab

Watchdog cron jobs should be no_agent=True. The script itself handles the decision logic (silent unless something changed). Wrapping it in an LLM agent adds unnecessary tokens and causes phantom typing indicators in Telegram. Set no_agent=True when creating/updating the cron job for this script.

Baseline Scores

Server	Score (out of 100)	Warnings
Netcup (core)	62	3 (vulnerable package, IPv6 DNS)
Hetzner wphost02	63	3 (to review)

Common warnings:

PKGS-7392: One or more vulnerable packages. Fix with apt-get update && apt-get upgrade.
NETW-2704/NETW-2705: Nameserver unreachable (often IPv6 DNS). Fix by disabling IPv6 DNS or adding working resolvers.

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