You might have heard of DoS, but this is not DOS (Disk Operating System) but DoS – Denial of service (DOS). It is a tool that is used by hackers to disrupt online services. These are of two types: denial of service and distributed denial of service (DDOS). The implications of such attacks are unthinkable and has cost companies millions. Anybody who runs a business is likely to face these attacks.

A DoS attack is launched from one machine, whereas DDoS attack is launched from many machines. A DoS attack leads to the website losing money as legitimate users cannot access the crowded network. DDoS attacks are worse than DoS attacks as they are launched from various computers; moreover, these are not just a couple of them but hundred and thousands of machines. They are not owned by the attacker but are machines that are infected by malware and have been added to the hacker’s network. This group of machines is known as Botnet.

It becomes frustrating in trying to defend your system against a DDoS attack. There are two different types of DDoS attacks–HTTP or SYN flooding.

• HTTP flooding means sending thousands of requests to the server in order to overwhelm it.
• The SYN attack floods the TCP network with unknown data packets. This attack has can have worrying consequences and can impact users even unrelated victim.

There can be many reasons for such an attack: it could be the companies are at war with each other on the internet; it could be someone seeking revenge; or activists orchestrating and attack; it could also be someone looking to make money by holding them to ransom.

Calculating the cost of loss by such an attack differentiates between DoS and DDos attacks. It can range from few hundred dollars to millions. Smaller companies feel the loss more than big companies. The worst scenario is the damage caused to the clients. Some DoS and DDoS cause distractions to cover the attack. It could lead to many clients losing their data. No one is safe from these attacks. For instance, in the year 2010, Twitter and PlayStation networks faced a DDoS attack and lost millions.

DoS attack is by a single machine and can be easily stopped by the right security. No malware is involved. It has a low threat level and is not used to cover a breach.

DDoS attack involves many computers. The threat level is high. It causes serious damage to the system and the network. A network of computers launching the DDoS is called the Botnet.

Protecting yourself from DOS attacks is very simple. You can block the attackers IP address at the firewall or ISP level. There are many tools which exist to block ICMP or SYN attacks.

DDoS is harder to safeguard against, but there are various methods. You can try to go through all the ISP addresses from the incoming traffic. This will help in saving the personal information. You can also use the SYN cookies or HTTP reverse proxies. These types of malware can come in through the backdoor and disable the anti-virus, infect the modems so you need to be careful. A DDoS attack can happen any day. If you have online assets, then get yourself a web security expert. They are costly but you never know when you will require the protection.