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DDOS attacks: An old nemesis returns to cripple your network

Once considered a cybersecurity threat of the past, Distributed Denial of Service (DDoS) attacks have re-emerged with a vengeance. DDoS attacks are wreaking havoc on enterprises and end users with alarming frequency.

Distributed Denial of Service is a cyberattack where multiple systems are compromised, often joined with a Trojan, and used to target a single system to exhaust resources so that legitimate users are denied access to resources. Websites or other online resources become so overloaded with bogus traffic that they become unusable. A well-orchestrated DDoS carried out by automated bots or programs has the power to knock a website offline. These attacks can cripple even the most established and largest organisations. An e-commerce business can no longer conduct online transactions, jeopardising sales. Emergency response services can no longer respond, putting lives in danger.

According to the VeriSign Distributed Denial of Service Trends Report, DDoS activity increased by 85 percent in one year. The report also suggested that cyber attackers are beginning to hit targets repeatedly, with some organisations the target of DDoS attacks up to 16 times in just three months. If you think your organisation is obscure and can fly under the cyber attacker radar – forget it. Every industry is vulnerable.

If an increase in attacks isn't troubling enough, the size and the amount of damage DDoS attacks can do is also disturbing. The fastest flood attack detected by Verisign occurred during the fourth quarter of 2015, targeting a telecommunications company by sending 125 million packets per second (Mpps), and driving a volumetric DDoS attack of 65 gigabits per second (Gbps). The end result – the site imploded and was temporarily knocked out of service.  

Why DDos attacks are back in vogue   

The reason why DDoS attacks are back is simple - it is relatively easy to launch a sustained attack and cripple any organisation connected to the Internet. Botnets, a group of computers connected for malicious purposes, can actually be acquired as a DDoS for hire service. The ability to acquire destructive assets demonstrates how easy it is for someone with little technical knowledge to attack any organisation.

DDoS attacks typically hit in three ways - Application Order, Volumetric, and Hybrid. Application orders cripple networks by potentially creating hundreds of thousands of connections at a time; volumetric attacks seek to overload a site with traffic; hybrid attacks can deliver the double whammy of knocking a business offline. The real danger of DDoS attacks is that they are often an end around. While technicians are pre-occupied with trying to get the website back up, attackers can often plant a backdoor in others areas of the network to eventually steal information.

How to prevent DDoS attacks

Prevention is nearly impossible, since there is no effective control of hackers in the outside world. A DDoS appliance protecting the Internet connection is the first line of defence. This will help to mitigate an attack. Appliances from vendors such as Fortinet or Radware are placed on customer premise as close to their Internet edge as possible. These devices can help to identify and block most DDoS traffic. However, this solution falls short with a DDoS attack that is attempting to flood Internet circuits. The only way to protect against this type of attack is to have a device at the service provider or in the cloud. A managed security services provider (MSSP) can offer on-demand services that are both cost effective and architected with a cloud focus in mind, in order to effectively protect against each type of attack.

A number of companies offer tools to analyse network traffic for signs of malicious activity, which can often weed out unwanted network connections. Infrastructure Access Control Lists (IACLs) can also be installed in routers and switches to detect suspicious traffic patterns and keep unwanted traffic off servers.

Many companies believe they can thwart attacks by hiding behind a firewall, but these general purpose tools are typically the first to fall. Firewalls offer some protection, but they can be easily hacked. Organisations expose themselves to attack when they use technology as a crutch. Winning the DDoS war requires organisations to look at their operations as a critical network and seek ways to defend it with talented individuals and technology that stay one step ahead of the attackers. A firewall is important but not a panacea.

The major drawback to do-it-yourself solutions is that they are reactive. Attackers can easily modify their methods and come at a business from disparate sources using different vectors. This keeps an organisation always in a defensive position, having to repeatedly deploy additional configurations, while simultaneously attempting to recover from any downtime events.

Many organisations have limited expertise and resource bandwidth to deal with the complexities of security and compliance. Managed security services providers with the ability to monitor, manage and protect control systems fill that cybersecurity gap. Detecting a DDoS attack requires specialised hardware capable of sending alerts via email or text. The goal is to report and respond to the incident before the attacker makes resources unavailable. An MSSP who employs both technology and on-site personnel can monitor and act as a full operations team.

If a DDoS attack is suspected, it is probably affecting the ISP as well. The security team should immediately contact the ISP to see if they can detect a DDoS attack and re-route traffic. Inquire whether any DDoS protective services are available, and consider a backup ISP as a contingency.

DDoS attacks will continue in the future due to the ease of execution. Companies must ensure they are prepared, constantly monitor the network, and have a game plan if an attack is under way. The daily headlines prove that no organisation is immune. With a little foresight it is possible to both thwart an attack and defend against future ones.  

Mike Baker is founder and Principal at Mosaic451, a bespoke cyber security service provider and consultancy with specific expertise in building, operating and defending some of the most highly-secure networks in North America.