Common Network Attacks
By: Engr. Ahmed Malik (Advisor to Cisco ASC/ITC & Director Tech Awareness)
Networks are frequent targets. A threat actor who gains administrative access to a corporate network infrastructure can:
- Steal data
- Delete data
- Disrupt network availability
To achieve their objectives, attackers commonly use the following three categories of network attacks:
- Reconnaissance Attacks
- Access Attacks
- Denial-of-Service (DoS) Attacks
1. Reconnaissance Attacks
Reconnaissance means information gathering. Similar to a thief surveying homes, attackers try to discover and map systems, services, or vulnerabilities before launching a major attack.
Common Techniques:
- Information Query – Using Google search, organization websites, Whois, etc.
- Ping Sweep – Identifying active IP addresses.
- Port Scanning – Tools: Nmap, SuperScan, Angry IP Scanner, NetScanTools.
- Vulnerability Scanning – Tools: Nessus, OpenVAS, Nipper, Secuna PSI.
- Exploitation Tools – Tools: Metasploit, Sqlmap, SET, Core Impact.
2. Access Attacks
These exploit vulnerabilities in authentication, FTP, or web services to gain unauthorized entry, retrieve confidential data, or escalate privileges.
Types of Access Attacks:
a. Password Attacks – Cracking system passwords using tools.
b. Spoofing Attacks – IP spoofing, MAC spoofing, DHCP spoofing.
c. Trust Exploitation – Misusing unauthorized privileges.
d. Port Redirection – Using a compromised system as a base for further attacks.
e. Man-in-the-Middle (MitM) – Intercepting and modifying communication.
f. Buffer Overflow – Overloading memory buffers, often leading to DoS.
g. Social Engineering Attacks – Manipulating humans to gain access.
Social Engineering Techniques:
- Pretexting
- Phishing & Spear Phishing
- Spam
- Baiting
- Impersonation
- Tailgating
- Shoulder Surfing
- Dumpster Diving
Note: The Social Engineering Toolkit (SET) helps security professionals test their networks against such attacks.
3. Denial-of-Service (DoS) and Distributed Denial-of-Service (DDoS) Attacks
DoS Attacks:
- Traffic Overload – Flooding with enormous data.
- Malformed Packets – Sending maliciously crafted packets to crash a device.
DDoS Attacks:
- Carried out via multiple infected devices (botnet).
- Controlled by a Command & Control (CnC) system.
- Zombies spread malware and launch massive coordinated attacks.
Other Common Network Attacks
1. Eavesdropping (Sniffing/Snooping)
Capturing and listening to network traffic.
2. Data Modification Attack
Altering packet data without detection.
3. IP Address Spoofing
Forging IP packets to appear legitimate.
4. Password-Based Attacks
Using stolen user accounts for unauthorized actions.
5. Man-in-the-Middle (MitM)
Intercepting communication between source and destination.
6. Compromised-Key Attack
Using stolen encryption keys for unauthorized access.
7. Sniffer Attack
Using applications/devices to capture unencrypted data packets.
Summary
- Reconnaissance Attacks: Information gathering (ping sweep, port scan, vulnerability scanning).
- Access Attacks: Exploiting authentication and trust (passwords, spoofing, MitM, buffer overflow, social engineering).
- DoS/DDoS Attacks: Disrupting services via traffic overload or botnets.
- Other Attacks: Eavesdropping, data modification, spoofing, compromised keys, sniffing.
📌 Source: CCNAv7 Enterprise, Networking, Security, and Automation Companion Guide
