Stealth Scanning Methods
Understanding Stealth Scanning
Stealth scanning is an advanced network reconnaissance technique designed to minimize detection by network security systems. The primary goal is to gather critical network information while avoiding triggering intrusion detection systems (IDS) or alerting network administrators.
Stealth Scanning Techniques
1. SYN Stealth Scan (Half-Open Scan)
sequenceDiagram
participant Attacker
participant Target
Attacker->>Target: SYN Packet
Target-->>Attacker: SYN-ACK
Attacker->>Target: RST Packet
Example Implementation
## SYN Stealth Scan using Nmap
sudo nmap -sS 192.168.1.100 -p 1-1000
2. FIN Scan Technique
Sends FIN packets to detect closed ports and bypass firewall rules.
## FIN Scan with Nmap
sudo nmap -sF 192.168.1.100
Stealth Scanning Methods Comparison
Scanning Method |
Detection Difficulty |
Packet Type |
Typical Use |
SYN Stealth |
Low |
TCP SYN |
Port Discovery |
FIN Scan |
Very Low |
TCP FIN |
Firewall Evasion |
Null Scan |
Very Low |
No Flags |
Advanced Reconnaissance |
XMAS Scan |
Low |
FIN, URG, PSH |
Complex Detection Bypass |
Advanced Stealth Techniques
Fragmentation Scanning
Breaking packets into smaller fragments to evade detection:
## Fragmentation Scan
sudo nmap -f 192.168.1.100
Decoy Scanning
Generating multiple fake source IP addresses to confuse defenders:
## Decoy Scan
sudo nmap -D 192.168.1.5,10.0.0.3,RND:10 192.168.1.100
Scanning Strategy Workflow
graph TD
A[Select Target] --> B[Choose Stealth Method]
B --> C[Configure Scanning Parameters]
C --> D[Execute Scan]
D --> E[Analyze Results]
E --> F[Generate Report]
Practical Considerations
Legal and Ethical Warnings
- Always obtain explicit permission
- Respect network usage policies
- Use for legitimate security testing only
Scanning Efficiency Factors
- Packet timing
- Source IP randomization
- Minimal packet signatures
- Adaptive scanning techniques
LabEx Cybersecurity Recommendation
When practicing stealth scanning techniques, always use controlled environments provided by LabEx training platforms to ensure safe and legal learning experiences.
Key Takeaways
- Stealth scanning minimizes detection risks
- Multiple techniques exist for different scenarios
- Careful implementation is crucial
- Ethical considerations are paramount