Distributed Denial of Service (DDoS) is a cyber-attack which begins by exploiting one computer system and gradually gains control over other vulnerable computers to attack a server, website or other networks. The hacker attains these computers under command and target systems with malware which causes them to slow down, crash the structure or even shut down along with dismissing services to authorized users. It is like a network congestion which stops the flow of incoming vital mails or data by flooding them server with hoax packets. There are number of viruses that can damage your computer beyond repair, but DDoS seems to be the really complicated one to detect as it is spread across multiple channels. It has been the cause of major financial losses for eminent companies as well as small business enterprises.
It is different from Denial of Service (DoS) as DoS attack uses one network to connect and flood a system with large extent of traffic and confusing the server to accept legit traffic generating the website to become inaccessible. While DDoS uses multiple networks to connect and flood the targeted server with malicious traffic but from one central location.
In simple words, this attack obstructs network services or connectivity that causes denial of services to users of intended resources. Now let’s go through some of the variations of DDoS attacks that are deployed to freeze and take over a website.
- Application level attacks- This attack exploits the fragility of a website and exhausts a server. It focuses mainly on the loopholes of single application and grows its channels making it hard to detect.
- Ping of Death- It is an attack that sends maneuvering pings to a system from Internet protocol (IP) and flooding it until the system goes offline or shuts down. It is devised to exhaust the network resources and drain it out. The ping flood is often mistaken as legitimate traffic resulting in getting hacked.
- Slow loris- A challenging attack to control, Slow loris targets web servers by keeping the connecting with the network and keeping it open for a long time with HTTP flooding until the website is crippled with nothing, all of these is acquired by using minimal resources. The perfect example would be the Slow loris attack used against in the 2009 Iranian presidential election.
- SYN Flood- The SYN attack abuses the three way communication/handshake of the Transmission Control Protocol (TCP) by sending synchronized or SYN messages to the target server from hoax IP address. They attempt to overload the connection by flooding the server with spoofed connections causing the system to become indifferent to authorized traffics.
The ‘three-way handshake’ means it engages in the process where the client sends a SYN packet to the server to commence the connection; the server responds by sending an acknowledgment or ACK packet; lastly the client returns an ACK packet to declare the delivery of the packet and establishes the connection to send and receive data.
- Teardrop attack- This attack involves sending large-scale of fragmented packets to the recipient system. Since the server is not able to reorganize the fragments into its initial form due to the virus in the TCP, the packets overlap one another which causes the network to crash altogether.
- UDP Flood- The User Datagram Protocol (UDP) targets a server with inordinate UDP packets. The attackers send random ports to the network which ensues the server to listen to these ports. When it is not able to discern the applications, the devices get exhausted oppressing its ability to operate and retaliate that results disproving to legitimate requests.
- Memcached attack- For speeding up of websites and networks memcached DDos attack is used. In this attack, the hackers sends spoofed requests to a defenseless server, responding to which the network makes connection. This opens up the route to vast malicious traffic to the server.
Since there are various forms of DDoS attacks and you never know which one you have to face, it’s suggested to take some precautionary measures to with stand these attacks.
- A Denial of Service resistant plan will be to guard your server with enough bandwidth. To do that it is best to buy additional bandwidth at your convenience so the attacker have to tackle with more obstacles to get to your network.
- The combination of firewalls, VPN, content filtering, and other antivirus software will safeguard your network from malicious virus.
- A team of influential and intellectual members should be formed who are ready to face the challenges of the attack whenever it happens.
- The cloud based service offers bandwidth and other resources to take in harmful traffic and is operated by analytical professionals which can also be useful for your global or small business .
- You can also spread your server across multiple data centers with different networks and a steady structure so that the traffic is distributed between them making it more complicated for the attackers to get it all at once.
- A Web Application Firewall (WAF) will detect the vulnerability in your applications or illegitimate request before processing it.
- Keep a backup support of every files and documents so when the originals are compromised, you are not left empty-handed.
- Last but not the least, always keep your antivirus updated so the attackers cannot find any loopholes.
Although it is difficult to perceive a DDoS attack, you can get a notion about it by clues like the server slowing down, inconsistent connectivity or network shut down. Before panicking take some time as most network links are defective. If the duration of lost network and other glitches is more than usual, it’s time to take action.
There are regular traffic which are pre-approved and are handled effectively. But some unnatural traffic can also include the attackers in packets, so you can develop a strategy where the packets are interpreted individually or compared with other request, and are accepted only when found legit. It can be time-consuming process, but it is better to be safe than regret later. There are many factors that are in stake here as a DDoS attack can lead to loss of reputation, brand debasement and the most important, loss of valuable customers. So it is advised to invest some money on productive antivirus software.