Scanning Tools

Core Workflow

Phase 1: Network Scanning Tools

Nmap (Network Mapper)

Primary tool for network discovery and security auditing:

# Host discovery
nmap -sn 192.168.1.0/24              # Ping scan (no port scan)
nmap -sL 192.168.1.0/24              # List scan (DNS resolution)
nmap -Pn 192.168.1.100               # Skip host discovery

# Port scanning techniques
nmap -sS 192.168.1.100               # TCP SYN scan (stealth)
nmap -sT 192.168.1.100               # TCP connect scan
nmap -sU 192.168.1.100               # UDP scan
nmap -sA 192.168.1.100               # ACK scan (firewall detection)

# Port specification
nmap -p 80,443 192.168.1.100         # Specific ports
nmap -p- 192.168.1.100               # All 65535 ports
nmap -p 1-1000 192.168.1.100         # Port range
nmap --top-ports 100 192.168.1.100   # Top 100 common ports

# Service and OS detection
nmap -sV 192.168.1.100               # Service version detection
nmap -O 192.168.1.100                # OS detection
nmap -A 192.168.1.100                # Aggressive (OS, version, scripts)

# Timing and performance
nmap -T0 192.168.1.100               # Paranoid (slowest, IDS evasion)
nmap -T4 192.168.1.100               # Aggressive (faster)
nmap -T5 192.168.1.100               # Insane (fastest)

# NSE Scripts
nmap --script=vuln 192.168.1.100     # Vulnerability scripts
nmap --script=http-enum 192.168.1.100  # Web enumeration
nmap --script=smb-vuln* 192.168.1.100  # SMB vulnerabilities
nmap --script=default 192.168.1.100  # Default script set

# Output formats
nmap -oN scan.txt 192.168.1.100      # Normal output
nmap -oX scan.xml 192.168.1.100      # XML output
nmap -oG scan.gnmap 192.168.1.100    # Grepable output
nmap -oA scan 192.168.1.100          # All formats

Masscan

High-speed port scanning for large networks:

# Basic scanning
masscan -p80 192.168.1.0/24 --rate=1000
masscan -p80,443,8080 192.168.1.0/24 --rate=10000

# Full port range
masscan -p0-65535 192.168.1.0/24 --rate=5000

# Large-scale scanning
masscan 0.0.0.0/0 -p443 --rate=100000 --excludefile exclude.txt

# Output formats
masscan -p80 192.168.1.0/24 -oG results.gnmap
masscan -p80 192.168.1.0/24 -oJ results.json
masscan -p80 192.168.1.0/24 -oX results.xml

# Banner grabbing
masscan -p80 192.168.1.0/24 --banners

Phase 2: Vulnerability Scanning Tools

Nessus

Enterprise-grade vulnerability assessment:

# Start Nessus service
sudo systemctl start nessusd

# Access web interface
# https://localhost:8834

# Command-line (nessuscli)
nessuscli scan --create --name "Internal Scan" --targets 192.168.1.0/24
nessuscli scan --list
nessuscli scan --launch <scan_id>
nessuscli report --format pdf --output report.pdf <scan_id>

Key Nessus features:

• Comprehensive CVE detection
• Compliance checks (PCI-DSS, HIPAA, CIS)
• Custom scan templates
• Credentialed scanning for deeper analysis
• Regular plugin updates

OpenVAS (Greenbone)

Open-source vulnerability scanning:

# Install OpenVAS
sudo apt install openvas
sudo gvm-setup

# Start services
sudo gvm-start

# Access web interface (Greenbone Security Assistant)
# https://localhost:9392

# Command-line operations
gvm-cli socket --xml "<get_version/>"
gvm-cli socket --xml "<get_tasks/>"

# Create and run scan
gvm-cli socket --xml '
<create_target>
  <name>Test Target</name>
  <hosts>192.168.1.0/24</hosts>
</create_target>'

Phase 3: Web Application Scanning Tools

Burp Suite

Comprehensive web application testing:

# Proxy configuration
1. Set browser proxy to 127.0.0.1:8080
2. Import Burp CA certificate for HTTPS
3. Add target to scope

# Key modules:
- Proxy: Intercept and modify requests
- Spider: Crawl web applications
- Scanner: Automated vulnerability detection
- Intruder: Automated attacks (fuzzing, brute-force)
- Repeater: Manual request manipulation
- Decoder: Encode/decode data
- Comparer: Compare responses

Core testing workflow:

1. Configure proxy and scope
2. Spider the application
3. Analyze sitemap
4. Run active scanner
5. Manual testing with Repeater/Intruder
6. Review findings and generate report

OWASP ZAP

Open-source web application scanner:

# Start ZAP
zaproxy

# Automated scan from CLI
zap-cli quick-scan https://target.com

# Full scan
zap-cli spider https://target.com
zap-cli active-scan https://target.com

# Generate report
zap-cli report -o report.html -f html

# API mode
zap.sh -daemon -port 8080 -config api.key=<your_key>

ZAP automation:

# Docker-based scanning
docker run -t owasp/zap2docker-stable zap-full-scan.py \
  -t https://target.com -r report.html

# Baseline scan (passive only)
docker run -t owasp/zap2docker-stable zap-baseline.py \
  -t https://target.com -r report.html

Nikto

Web server vulnerability scanner:

# Basic scan
nikto -h https://target.com

# Scan specific port
nikto -h target.com -p 8080

# Scan with SSL
nikto -h target.com -ssl

# Multiple targets
nikto -h targets.txt

# Output formats
nikto -h target.com -o report.html -Format html
nikto -h target.com -o report.xml -Format xml
nikto -h target.com -o report.csv -Format csv

# Tuning options
nikto -h target.com -Tuning 123456789  # All tests
nikto -h target.com -Tuning x          # Exclude specific tests

Phase 4: Wireless Scanning Tools

Aircrack-ng Suite

Wireless network penetration testing:

# Check wireless interface
airmon-ng

# Enable monitor mode
sudo airmon-ng start wlan0

# Scan for networks
sudo airodump-ng wlan0mon

# Capture specific network
sudo airodump-ng -c <channel> --bssid <target_bssid> -w capture wlan0mon

# Deauthentication attack
sudo aireplay-ng -0 10 -a <bssid> wlan0mon

# Crack WPA handshake
aircrack-ng -w wordlist.txt -b <bssid> capture*.cap

# Crack WEP
aircrack-ng -b <bssid> capture*.cap

Kismet

Passive wireless detection:

# Start Kismet
kismet

# Specify interface
kismet -c wlan0

# Access web interface
# http://localhost:2501

# Detect hidden networks
# Kismet passively collects all beacon frames
# including those from hidden SSIDs

Phase 5: Malware and Exploit Scanning

ClamAV

Open-source antivirus scanning:

# Update virus definitions
sudo freshclam

# Scan directory
clamscan -r /path/to/scan

# Scan with verbose output
clamscan -r -v /path/to/scan

# Move infected files
clamscan -r --move=/quarantine /path/to/scan

# Remove infected files
clamscan -r --remove /path/to/scan

# Scan specific file types
clamscan -r --include='\.exe$|\.dll$' /path/to/scan

# Output to log
clamscan -r -l scan.log /path/to/scan

Metasploit Vulnerability Validation

Validate vulnerabilities with exploitation:

# Start Metasploit
msfconsole

# Database setup
msfdb init
db_status

# Import Nmap results
db_import /path/to/nmap_scan.xml

# Vulnerability scanning
use auxiliary/scanner/smb/smb_ms17_010
set RHOSTS 192.168.1.0/24
run

# Auto exploitation
vulns                           # View vulnerabilities
analyze                         # Suggest exploits

Phase 6: Cloud Security Scanning

Prowler (AWS)

AWS security assessment:

# Install Prowler
pip install prowler

# Basic scan
prowler aws

# Specific checks
prowler aws -c iam s3 ec2

# Compliance framework
prowler aws --compliance cis_aws

# Output formats
prowler aws -M html json csv

# Specific region
prowler aws -f us-east-1

# Assume role
prowler aws -R arn:aws:iam::123456789012:role/ProwlerRole

ScoutSuite (Multi-cloud)

Multi-cloud security auditing:

# Install ScoutSuite
pip install scoutsuite

# AWS scan
scout aws

# Azure scan
scout azure --cli

# GCP scan
scout gcp --user-account

# Generate report
scout aws --report-dir ./reports

Phase 7: Compliance Scanning

Lynis

Security auditing for Unix/Linux:

# Run audit
sudo lynis audit system

# Quick scan
sudo lynis audit system --quick

# Specific profile
sudo lynis audit system --profile server

# Output report
sudo lynis audit system --report-file /tmp/lynis-report.dat

# Check specific section
sudo lynis show profiles
sudo lynis audit system --tests-from-group malware

OpenSCAP

Security compliance scanning:

# List available profiles
oscap info /usr/share/xml/scap/ssg/content/ssg-<distro>-ds.xml

# Run scan with profile
oscap xccdf eval --profile xccdf_org.ssgproject.content_profile_pci-dss \
  --report report.html \
  /usr/share/xml/scap/ssg/content/ssg-rhel8-ds.xml

# Generate fix script
oscap xccdf generate fix \
  --profile xccdf_org.ssgproject.content_profile_pci-dss \
  --output remediation.sh \
  /usr/share/xml/scap/ssg/content/ssg-rhel8-ds.xml

Phase 8: Scanning Methodology

Structured scanning approach:

1. Planning

   • Define scope and objectives
   • Obtain proper authorization
   • Select appropriate tools

2. Discovery

   • Host discovery (Nmap ping sweep)
   • Port scanning
   • Service enumeration

3. Vulnerability Assessment

   • Automated scanning (Nessus/OpenVAS)
   • Web application scanning (Burp/ZAP)
   • Manual verification

4. Analysis

   • Correlate findings
   • Eliminate false positives
   • Prioritize by severity

5. Reporting

   • Document findings
   • Provide remediation guidance
   • Executive summary

Phase 9: Tool Selection Guide

Choose the right tool for each scenario:

Phase 10: Reporting and Documentation

Generate professional reports:

# Nmap XML to HTML
xsltproc nmap-output.xml -o report.html

# OpenVAS report export
gvm-cli socket --xml '<get_reports report_id="<id>" format_id="<pdf_format>"/>'

# Combine multiple scan results
# Use tools like Faraday, Dradis, or custom scripts

# Executive summary template:
# 1. Scope and methodology
# 2. Key findings summary
# 3. Risk distribution chart
# 4. Critical vulnerabilities
# 5. Remediation recommendations
# 6. Detailed technical findings

Quick Reference

Nmap Cheat Sheet

Common Ports Reference

Constraints and Limitations

Legal Considerations

• Always obtain written authorization
• Respect scope boundaries
• Follow responsible disclosure practices
• Comply with local laws and regulations

Technical Limitations

• Some scans may trigger IDS/IPS alerts
• Heavy scanning can impact network performance
• False positives require manual verification
• Encrypted traffic may limit analysis

Best Practices

• Start with non-intrusive scans
• Gradually increase scan intensity
• Document all scanning activities
• Validate findings before reporting

Troubleshooting

Scan Not Detecting Hosts

Solutions:

1. Try different discovery methods: nmap -Pn or nmap -sn -PS/PA/PU
2. Check firewall rules blocking ICMP
3. Use TCP SYN scan: nmap -PS22,80,443
4. Verify network connectivity

Slow Scan Performance

Solutions:

1. Increase timing: nmap -T4 or -T5
2. Reduce port range: --top-ports 100
3. Use Masscan for initial discovery
4. Disable DNS resolution: -n

Web Scanner Missing Vulnerabilities

Solutions:

1. Authenticate to access protected areas
2. Increase crawl depth
3. Add custom injection points
4. Use multiple tools for coverage
5. Perform manual testing

When to Use

This skill is applicable to execute the workflow or actions described in the overview.