Ethical Hacking Essentials Practice Test

Which layer of the vulnerability stack do evasion techniques target to avoid detection by IDS/IPS?

1. Layer 1

2. Layer 2

3. Layer 3

4. Layer 4

The correct answer is: Layer 1

Evasion techniques specifically target the Layer 3 and Layer 4 of the OSI model when trying to avoid detection by Intrusion Detection Systems (IDS) and Intrusion Prevention Systems (IPS). This is because these layers are responsible for transport and network-level data handling, where packets are constructed and managed. Layer 4, the transport layer, is particularly significant in evasion techniques because it helps control the flow of data between hosts and may allow attackers to manipulate packet headers, use stealth techniques like fragmentation, and alter protocol flags to bypass detection mechanisms. While Layer 1 and Layer 2 deal with physical and data link layers, respectively, they are not primarily where evasion techniques focus regarding IDS/IPS evasion. Instead, they deal more with routing and initial data framing, which does not usually concern the advanced strategies hackers use to hide malicious traffic from detection systems. By understanding the specific layers these techniques focus on, cybersecurity professionals can better design their defenses to recognize and respond to such evasion tactics, ensuring more effective network security.