Network Attack Techniques
Network security attacks are unauthorized actions against private, corporate or governmental IT assets in order to destroy them, modify them or steal sensitive data. As more enterprises invite employees to access data from mobile devices, networks become vulnerable to data theft or total destruction of the data or network.
1.Denial-of-Service:-
A denial-of-service attack overwhelms a system's resources so that it cannot respond to service requests. A DDoS attack is also an attack on system resources , but it is launched from a large number of other host machines that are infected by malicious software controlled by the attacker.
A.TCP SYN flood attack:-
An attacker exploits the use of the buffer space during a Transmission Control Protocol (TCP) session initialization handshake. The attacker’s device floods the target system’s small in-process queue with connection requests, but it does not respond when the target system replies to those requests. This causes the target system to time out while waiting for the response from the attacker’s device, which makes the system crash or become unusable when the connection queue fills up.
B. Teardrop Attack:-
This attack causes the length and fragmentation offset fields in sequential Internet Protocol (IP) packets to overlap one another on the attacked host; the attacked system attempts to reconstruct packets during the process but fails. The target system then becomes confused and crashes.
C. Smurf Attack:-
This attack involves using IP spoofing and the ICMP to saturate a target network with traffic. This attack method uses ICMP echo requests targeted at broadcast IP addresses. These ICMP requests originate from a spoofed “victim” address. For instance, if the intended victim address is 10.0.0.10, the attacker would spoof an ICMP echo request from 10.0.0.10 to the broadcast address 10.255.255.255. This request would go to all IPs in the range, with all the responses going back to 10.0.0.10, overwhelming the network. This process is repeatable, and can be automated to generate huge amounts of network congestion.
D. Ping of Death Attack:-
This type of attack uses IP packets to ‘ping a target system with an IP size over the maximum of 65,535 bytes. IP packets of this size are not allowed, so attacker fragments the IP packet. Once the target system reassembles the packet, it can experience buffer overflows and other crashes. Ping of death attacks can be blocked by using a firewall that will check fragmented IP packets for maximum size.
E. Botnets:-
Botnets are the millions of systems infected with malware under hacker control in order to carry out DDoS attacks. These bots or zombie systems are used to carry out attacks against the target systems, often overwhelming the target system’s bandwidth and processing capabilities. These DDoS attacks are difficult to trace because botnets are located in differing geographic locations.
2.Man-in-the -middle:-
A MitM attack occurs when a hacker inserts itself between the communications of a client and a server.
A. Session Hijacking:-
In this type of MitM attack, an attacker hijacks a session between a trusted client and network server. The attacking computer substitutes its IP address for the trusted client while the server continues the session, believing it is communicating with the client.
B. IP Spoofing :-
IP spoofing is used by an attacker to convince a system that it is communicating with a known, trusted entity and provide the attacker with access to the system. The attacker sends a packet with the IP source address of a known, trusted host instead of its own IP source address to a target host. The target host might accept the packet and act upon it.
C. Replay:-
A replay attack occurs when an attacker intercepts and saves old messages and then tries to send them later, impersonating one of the participants. This type can be easily countered with session timestamps or nonce.
3.Phishing And Spear Phishing Attacks :-
Phishing attack is the practice of sending emails that appear to be from trusted sources with the goal of gaining personal information or influencing users to do something. It combines social engineering and technical trickery. It could involve an attachment to an email that loads malware onto your computer. It could also be a link to an illegitimate website that can trick you into downloading malware or handing over your personal information. Spear phishing is a very targeted type of phishing activity. Attackers take the time to conduct research into targets and create messages that are personal and relevant. Because of this, spear phishing can be very hard to identify and even harder to defend against. One of the simplest ways that a hacker can conduct a spear phishing attack is email spoofing, which is when the information in the “From” section of the email is falsified, making it appear as if it is coming from someone you know, such as your management or your partner company. Another technique that scammers use to add credibility to their story is website cloning — they copy legitimate websites to fool you into entering personally identifiable information (PII) or login credential.
4.Drive-by Attack:-
Drive-by download attacks are a common method of spreading malware. Hackers look for insecure websites and plant a malicious script into HTTP or PHP code on one of the pages. This script might install malware directly onto the computer of someone who visits the site, or it might re-direct the victim to a site controlled by the hackers. Drive-by downloads can happen when visiting a website or viewing an email message or a pop-up window. Unlike many other types of cyber security attacks, a drive-by doesn’t rely on a user to do anything to actively enable the attack — you don’t have to click a download button or open a malicious email attachment to become infected. A drive-by download can take advantage of an app, operating system or web browser that contains security flaws due to unsuccessful updates or lack of updates.
