Set up audit log analysis dashboard with Grafana and Prometheus for security monitoring

Update system packages

Start by updating your package manager to ensure you get the latest security patches and package versions.

sudo apt update && sudo apt upgrade -y

sudo dnf update -y

Install audit daemon and dependencies

Install auditd for system auditing, along with tools for log processing and metric collection. This includes the audit daemon, log utilities, and Python tools for custom exporters.

sudo apt install -y auditd audispd-plugins python3-pip python3-venv curl wget jq
sudo pip3 install prometheus_client psutil

sudo dnf install -y audit audit-libs python3-pip curl wget jq
sudo pip3 install prometheus_client psutil

Configure audit rules for security monitoring

Create comprehensive audit rules that monitor file access, user authentication, privilege changes, and network connections. These rules capture security-relevant events without overwhelming the system with noise.

# Delete existing rules
-D

Set buffer size
-b 8192

Set failure mode (2 = panic on failure)
-f 1

Monitor authentication events
-w /etc/passwd -p wa -k identity
-w /etc/group -p wa -k identity
-w /etc/shadow -p wa -k identity
-w /etc/sudoers -p wa -k privilege_escalation
-w /etc/sudoers.d/ -p wa -k privilege_escalation

Monitor login/logout events
-w /var/log/faillog -p wa -k logins
-w /var/log/lastlog -p wa -k logins
-w /var/log/tallylog -p wa -k logins

Monitor network configuration
-w /etc/hosts -p wa -k network_config
-w /etc/network/ -p wa -k network_config

Monitor cron jobs
-w /etc/cron.allow -p wa -k cron
-w /etc/cron.deny -p wa -k cron
-w /etc/cron.d/ -p wa -k cron
-w /etc/cron.daily/ -p wa -k cron
-w /etc/cron.hourly/ -p wa -k cron
-w /etc/cron.monthly/ -p wa -k cron
-w /etc/cron.weekly/ -p wa -k cron
-w /etc/crontab -p wa -k cron

Monitor SSH configuration
-w /etc/ssh/sshd_config -p wa -k ssh_config

Monitor system calls
-a always,exit -F arch=b64 -S adjtimex -S settimeofday -k time_change
-a always,exit -F arch=b32 -S adjtimex -S settimeofday -S stime -k time_change
-a always,exit -F arch=b64 -S mount -k mounts
-a always,exit -F arch=b32 -S mount -k mounts

Monitor file deletions
-a always,exit -F arch=b64 -S unlink -S unlinkat -S rename -S renameat -k delete
-a always,exit -F arch=b32 -S unlink -S unlinkat -S rename -S renameat -k delete

Make rules immutable
-e 2

Configure auditd daemon

Configure auditd with appropriate log rotation, formatting, and performance settings. This ensures logs are captured efficiently without filling up disk space.

log_file = /var/log/audit/audit.log
log_format = RAW
log_group = adm
priority_boost = 4
flush = INCREMENTAL_ASYNC
freq = 50
num_logs = 10
max_log_file = 100
max_log_file_action = ROTATE
space_left = 500
space_left_action = SYSLOG
admin_space_left = 100
admin_space_left_action = SUSPEND
disk_full_action = SUSPEND
disk_error_action = SUSPEND

Install and configure Prometheus Node Exporter

Download and install Prometheus Node Exporter to collect system metrics. This will work alongside our custom audit exporter to provide comprehensive monitoring data.

cd /tmp
wget https://github.com/prometheus/node_exporter/releases/download/v1.7.0/node_exporter-1.7.0.linux-amd64.tar.gz
tar xfz node_exporter-1.7.0.linux-amd64.tar.gz
sudo mv node_exporter-1.7.0.linux-amd64/node_exporter /usr/local/bin/
sudo useradd --no-create-home --shell /bin/false node_exporter
sudo chown node_exporter:node_exporter /usr/local/bin/node_exporter

Create Node Exporter systemd service

Create a systemd service file for Node Exporter to run automatically on system startup with proper security isolation.

[Unit]
Description=Node Exporter
After=network.target

[Service]
User=node_exporter
Group=node_exporter
Type=simple
ExecStart=/usr/local/bin/node_exporter --web.listen-address=:9100
Restart=always
RestartSec=3

[Install]
WantedBy=multi-user.target

Create custom audit log exporter

Build a custom Python exporter that parses audit logs and exposes security metrics to Prometheus. This exporter will track authentication failures, privilege escalations, and file access patterns.

#!/usr/bin/env python3
import re
import time
import subprocess
from collections import defaultdict, deque
from prometheus_client import start_http_server, Counter, Gauge, Histogram
import threading

Prometheus metrics
auth_failures = Counter('audit_authentication_failures_total', 'Authentication failures', ['user', 'source'])
auth_successes = Counter('audit_authentication_successes_total', 'Authentication successes', ['user', 'source'])
privilege_escalations = Counter('audit_privilege_escalations_total', 'Privilege escalations', ['user', 'command'])
file_accesses = Counter('audit_file_accesses_total', 'File accesses', ['user', 'file', 'action'])
sudo_commands = Counter('audit_sudo_commands_total', 'Sudo commands executed', ['user', 'command'])
login_events = Counter('audit_login_events_total', 'Login events', ['user', 'type', 'result'])
cron_changes = Counter('audit_cron_changes_total', 'Cron configuration changes', ['user', 'file'])
ssh_events = Counter('audit_ssh_events_total', 'SSH events', ['user', 'event_type'])

Gauges for current state
active_sessions = Gauge('audit_active_sessions', 'Currently active user sessions')
failed_login_rate = Gauge('audit_failed_login_rate_per_minute', 'Failed login attempts per minute')

Rate tracking
failed_logins_window = deque(maxlen=100)

class AuditLogParser:
    def __init__(self):
        self.patterns = {
            'auth_failure': re.compile(r'type=USER_AUTH.res=failed.uid=(\d+).*auid=(\d+)'),
            'auth_success': re.compile(r'type=USER_AUTH.res=success.uid=(\d+).*auid=(\d+)'),
            'sudo_command': re.compile(r'type=USER_CMD.uid=(\d+).cmd="([^"]+)"'),
            'file_access': re.compile(r'type=PATH.name="([^"]+)".uid=(\d+)'),
            'user_start': re.compile(r'type=USER_START.uid=(\d+).auid=(\d+)'),
            'user_end': re.compile(r'type=USER_END.uid=(\d+).auid=(\d+)'),
            'cron_change': re.compile(r'key="cron".name="([^"]+)".uid=(\d+)'),
            'ssh_login': re.compile(r'type=USER_LOGIN.uid=(\d+).addr=([\d\.]+)')
        }
        
    def get_username(self, uid):
        try:
            result = subprocess.run(['getent', 'passwd', str(uid)], 
                                  capture_output=True, text=True, timeout=5)
            if result.returncode == 0:
                return result.stdout.split(':')[0]
        except:
            pass
        return f'uid_{uid}'
    
    def parse_line(self, line):
        current_time = time.time()
        
        # Authentication failures
        match = self.patterns['auth_failure'].search(line)
        if match:
            uid = match.group(1)
            user = self.get_username(uid)
            failed_logins_window.append(current_time)
            auth_failures.labels(user=user, source='unknown').inc()
            
        # Authentication successes
        match = self.patterns['auth_success'].search(line)
        if match:
            uid = match.group(1)
            user = self.get_username(uid)
            auth_successes.labels(user=user, source='unknown').inc()
            
        # Sudo commands
        match = self.patterns['sudo_command'].search(line)
        if match:
            uid = match.group(1)
            cmd = match.group(2)[:50]  # Truncate long commands
            user = self.get_username(uid)
            sudo_commands.labels(user=user, command=cmd).inc()
            privilege_escalations.labels(user=user, command=cmd).inc()
            
        # File access
        match = self.patterns['file_access'].search(line)
        if match:
            filepath = match.group(1)
            uid = match.group(2)
            user = self.get_username(uid)
            # Only track sensitive file access
            if any(sensitive in filepath for sensitive in ['/etc/passwd', '/etc/shadow', '/var/log']):
                file_accesses.labels(user=user, file=filepath, action='access').inc()
                
        # Cron changes
        match = self.patterns['cron_change'].search(line)
        if match:
            filepath = match.group(1)
            uid = match.group(2)
            user = self.get_username(uid)
            cron_changes.labels(user=user, file=filepath).inc()
            
        # SSH events
        match = self.patterns['ssh_login'].search(line)
        if match:
            uid = match.group(1)
            addr = match.group(2)
            user = self.get_username(uid)
            ssh_events.labels(user=user, event_type='login').inc()
    
    def update_gauges(self):
        # Calculate failed login rate
        current_time = time.time()
        recent_failures = sum(1 for t in failed_logins_window if current_time - t < 60)
        failed_login_rate.set(recent_failures)
        
        # Update active sessions (simplified)
        try:
            result = subprocess.run(['who', '-q'], capture_output=True, text=True, timeout=5)
            if result.returncode == 0:
                lines = result.stdout.strip().split('\n')
                if len(lines) > 1:
                    count_line = lines[-1]
                    count = int(count_line.split('=')[1].strip()) if '=' in count_line else 0
                    active_sessions.set(count)
        except:
            pass

def tail_audit_log(parser):
    try:
        process = subprocess.Popen(['tail', '-F', '/var/log/audit/audit.log'], 
                                 stdout=subprocess.PIPE, stderr=subprocess.PIPE, 
                                 universal_newlines=True)
        
        for line in iter(process.stdout.readline, ''):
            if line:
                parser.parse_line(line.strip())
    except Exception as e:
        print(f"Error reading audit log: {e}")
        time.sleep(5)

def update_metrics_periodically(parser):
    while True:
        parser.update_gauges()
        time.sleep(30)

if __name__ == '__main__':
    # Start metrics server
    start_http_server(9101)
    print("Audit exporter started on port 9101")
    
    parser = AuditLogParser()
    
    # Start gauge update thread
    gauge_thread = threading.Thread(target=update_metrics_periodically, args=(parser,))
    gauge_thread.daemon = True
    gauge_thread.start()
    
    # Start log tailing (blocking)
    while True:
        try:
            tail_audit_log(parser)
        except KeyboardInterrupt:
            break
        except Exception as e:
            print(f"Error in main loop: {e}")
            time.sleep(10)

Make audit exporter executable and create service

Set proper permissions for the audit exporter script and create a systemd service to run it automatically.

sudo chmod +x /usr/local/bin/audit_exporter.py
sudo useradd --no-create-home --shell /bin/false audit_exporter
sudo usermod -a -G adm audit_exporter

[Unit]
Description=Audit Log Prometheus Exporter
After=network.target auditd.service
Requires=auditd.service

[Service]
User=audit_exporter
Group=audit_exporter
Type=simple
ExecStart=/usr/bin/python3 /usr/local/bin/audit_exporter.py
Restart=always
RestartSec=10
StandardOutput=journal
StandardError=journal

[Install]
WantedBy=multi-user.target

Install Prometheus

Download and install Prometheus to collect metrics from both Node Exporter and our custom audit exporter.

cd /tmp
wget https://github.com/prometheus/prometheus/releases/download/v2.48.0/prometheus-2.48.0.linux-amd64.tar.gz
tar xfz prometheus-2.48.0.linux-amd64.tar.gz
sudo mv prometheus-2.48.0.linux-amd64/prometheus /usr/local/bin/
sudo mv prometheus-2.48.0.linux-amd64/promtool /usr/local/bin/
sudo useradd --no-create-home --shell /bin/false prometheus
sudo mkdir -p /etc/prometheus /var/lib/prometheus
sudo chown prometheus:prometheus /etc/prometheus /var/lib/prometheus

Configure Prometheus

Create a Prometheus configuration that scrapes metrics from both exporters and includes basic alerting rules for security events.

global:
  scrape_interval: 15s
  evaluation_interval: 15s

rule_files:
  - "/etc/prometheus/alert_rules.yml"

alerting:
  alertmanagers:
    - static_configs:
        - targets:
          - localhost:9093

scrape_configs:
  - job_name: 'prometheus'
    static_configs:
      - targets: ['localhost:9090']
        
  - job_name: 'node_exporter'
    static_configs:
      - targets: ['localhost:9100']
        
  - job_name: 'audit_exporter'
    static_configs:
      - targets: ['localhost:9101']
    scrape_interval: 30s

Create Prometheus alerting rules

Define alerting rules that trigger on suspicious security events like multiple authentication failures, privilege escalations, or unusual file access patterns.

groups:
  - name: security_alerts
    rules:
      - alert: HighAuthenticationFailures
        expr: increase(audit_authentication_failures_total[5m]) > 10
        for: 2m
        labels:
          severity: warning
        annotations:
          summary: "High number of authentication failures"
          description: "User {{ $labels.user }} has {{ $value }} authentication failures in the last 5 minutes"
          
      - alert: PrivilegeEscalation
        expr: increase(audit_privilege_escalations_total[10m]) > 5
        for: 1m
        labels:
          severity: critical
        annotations:
          summary: "Multiple privilege escalations detected"
          description: "User {{ $labels.user }} executed {{ $value }} sudo commands in 10 minutes"
          
      - alert: SensitiveFileAccess
        expr: increase(audit_file_accesses_total{file=~".(/etc/passwd|/etc/shadow|/var/log/.).*"}[5m]) > 3
        for: 1m
        labels:
          severity: warning
        annotations:
          summary: "Unusual access to sensitive files"
          description: "User {{ $labels.user }} accessed sensitive file {{ $labels.file }} {{ $value }} times in 5 minutes"
          
      - alert: CronConfigurationChanges
        expr: increase(audit_cron_changes_total[30m]) > 0
        for: 0m
        labels:
          severity: warning
        annotations:
          summary: "Cron configuration modified"
          description: "User {{ $labels.user }} modified cron file {{ $labels.file }}"
          
      - alert: HighFailedLoginRate
        expr: audit_failed_login_rate_per_minute > 20
        for: 3m
        labels:
          severity: critical
        annotations:
          summary: "High rate of failed login attempts"
          description: "{{ $value }} failed login attempts per minute detected - possible brute force attack"
          
  - name: system_health
    rules:
      - alert: AuditExporterDown
        expr: up{job="audit_exporter"} == 0
        for: 5m
        labels:
          severity: critical
        annotations:
          summary: "Audit exporter is down"
          description: "The audit log exporter has been down for more than 5 minutes"
          
      - alert: NodeExporterDown
        expr: up{job="node_exporter"} == 0
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "Node exporter is down"
          description: "The node exporter has been down for more than 5 minutes"

Create Prometheus systemd service

Set up Prometheus to run as a systemd service with proper permissions and security settings.

sudo chown -R prometheus:prometheus /etc/prometheus

[Unit]
Description=Prometheus
After=network.target

[Service]
User=prometheus
Group=prometheus
Type=simple
ExecStart=/usr/local/bin/prometheus \
  --config.file=/etc/prometheus/prometheus.yml \
  --storage.tsdb.path=/var/lib/prometheus/ \
  --web.console.templates=/etc/prometheus/consoles \
  --web.console.libraries=/etc/prometheus/console_libraries \
  --web.listen-address=0.0.0.0:9090 \
  --web.enable-lifecycle \
  --storage.tsdb.retention.time=30d
Restart=always
RestartSec=3

[Install]
WantedBy=multi-user.target

Install Grafana

Install Grafana to create dashboards for visualizing audit logs and security metrics from Prometheus.

curl -fsSL https://packages.grafana.com/gpg.key | sudo gpg --dearmor -o /usr/share/keyrings/grafana.gpg
echo "deb [signed-by=/usr/share/keyrings/grafana.gpg] https://packages.grafana.com/oss/deb stable main" | sudo tee /etc/apt/sources.list.d/grafana.list
sudo apt update
sudo apt install -y grafana

sudo tee /etc/yum.repos.d/grafana.repo <