Attacks on Networks

Sniffing (= reading the content of transmitted data packets) is one of the most popular reconnaissance methods used by the attackers to collect the information, such as: user IDs, passwords, session ids, confidential details, business discussions, and financial transactions. Other popular methods are pinging (= sending requests to a website to test its reachability and speed), banner grabbing (= finding a network's software version information), and port scanning (= determining which ports on a network are open and could be receiving or sending data.)

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The main purpose of Denial of Service (DOS) attacks is to make the network resources inaccessible to the user and bring down the network itself by generating a huge amount of network traffic that overwhelms or crashes the server, exceeding the capacity of the routers and switches or overwhelming CPU and memory.

Sometimes, the attacker gets into one device in the network remotely and triggers simultaneous exploitation of systems on the network or uses multiple compromised machines to initiate simultaneous attacks. The sudden increase in the network traffic can cause the server or router to go down quickly and become inaccessible to the legitimate users. This kind of an attack is called Distributed Denial-of-Service (DDOS), which hides the true origin of the attack.