Common DDoS Attacks

• SYN Flood Attack: An SYN Flood attack works similarly a mischievous child keeps on ringing the doorbell (request) and running away. The old person inside comes out, opens the door, and does not see anyone (no response). Ultimately, after frequent such scenarios, the old person gets exhausted and does not answer even genuine people. An SYN attack exploits TCP Handshake by sending out SYN messages with a spoofed IP address. The victim server keeps on responding but does not receive a final acknowledgment. 

• HTTP Flood Attack: In an HTTP Flood attack, multiple HTTP requests are generated simultaneously against a target server. This leads to the exhaustion of network resources of that server and thus fails to serve actual users’ requests. The variations of HTTP Flood attacks are – HTTP GET attacks and HTTP POST attacks. 

• DNS Amplification: Assume a scenario where you call Pizza Hut and ask them to call you back on a number and tell all the combinations of pizzas they have along with the toppings and desserts. You generated a large output with a very small input. But, the catch is the number you gave them is not yours. Similarly, DNS Amplification works by requesting a DNS server from a spoofed IP address and structuring your request so that the DNS server responds with a large amount of data to the target victim. 

Imagine a scenario where you are visiting some websites and one of them seems to be a little slow. You might blame their servers for improving their scalability as they might be experiencing a lot of user traffic on their site. Most of the sites already take this issue into account beforehand. Chances are, they might be a victim of what is known as a DDoS attack, Distributed Denial of Service Attack.

In a DDoS attack, the attacker tries to make a particular service unavailable by directing continuous and huge traffic from multiple end systems. Due to this enormous traffic, the network resources get utilized in serving requests of those false end systems such that, a legitimate user is unable to access the resources for themselves.