I’ll huff and I’ll puff and I’ll…bring your web application offline!
The possibility of a business being targeted by some huge zombie army, or botnet, is enough to send shivers down the spine of many seasoned security veterans. Modern botnets are of vast size and power, with more sophisticated features and capabilities than ever before. Modern botnet attacks can be very precise and controlled, being pulsed and sent in different ways to make the attackers impossible to trace and the impact that much more damaging. So who is behind these botnets, what can we expect to see in the future and how can organisations put their fears to bed and defend themselves effectively from them?
Botnets have transformed the DDoS landscape. Once, attacks were the preserve of a small, technical elite who had enough coding skills to launch a strike. But now, DDoS-for-hire botnets have significantly lowered the barriers to entry. A quick Google search and a PayPal account makes botnets readily available for just a few dozen dollars, with no coding experience necessary. And they are becoming increasingly popular – DDoS-for-hire botnets are now estimated to be behind as many as 40 per cent of all network layer attacks.
But while the majority of purchasers are likely to be low-level attackers, seeking to cause mischief and settle personal grievances, more powerful botnets-for-hire are also being utilised by state actors and organised crime syndicates. In recent years, DDoS attacks have been getting bigger and bigger. Our Security Operations Centre recorded a dramatic (25%) increase in very large attacks of more than 10Gb per second among our customer base in the second half of last year. And in terms of individual attacks, the strike on the BBC in January was one of the biggest ever reported, at an enormous 600Gb per second. While these attacks clearly cause significant damage, we believe that their primary purpose is often just to demonstrate their attackers’ capabilities so that they can be sold as a service in the future. The kind of gigantic attacks that make headlines aren’t cheap to rent, and would probably cost upwards of $150,000 to engage. As a result, these are only likely to be utilised by criminal or nation state attackers, who have access to a sophisticated infrastructure with money laundering capabilities.
Looking forward, there is really no limit to the potential size and scale of future botnet-driven DDoS attacks, particularly when they harness the full range of smart devices incorporated into our Internet of Things. By using amplification techniques on the millions of very high bandwidth density devices currently accessible, such as baby video monitors and security cameras, DDoS attacks are set to become even more colossal in scale. Terabit -class attacks may be increasingly common and ‘breaking the Internet’ – or at least clogging it in certain regions – could soon become a reality. The bottom line is that attacks of this size can take virtually any company offline, and are a reality that anyone with an online presence must be prepared to defend against..
But it isn’t just the giant attacks that organisations need to worry about. Before botnets are mobilised, hackers need to make sure that their techniques are going to work. This is usually done through the use of small, sub-saturating attacks which most IT teams wouldn’t even recognise as a DDoS attack. Due to their size – the majority are less than five minutes in duration and under 1Gbps – these shorter attacks typically evade detection by most legacy out-of-band DDoS mitigation tools, which are generally configured with detection thresholds that ignore this level of activity. This allows hackers to perfect their methods under the radar, leaving security teams blindsided by subsequent attacks. If these techniques are then deployed at full scale with a botnet, the results can be devastating.
Besides harnessing enormous power, botnets are also notoriously difficult to spot. Once deployed, they utilise sophisticated techniques to hide their tracks. Their command and control infrastructure can be automated or set on autopilot, they can sleep for long periods of time, they can have ubiquitous bandwidth available at any time of day by waking up different regions at different times – they are a complex and vast maze, often operated by some of the brightest minds in cybercrime. But that’s no reason for organisations to resign themselves to eventually getting attacked. So what are the most effective methods of defence?
The old way was to use a cloud-based scrubbing centre, where the security team can divert traffic for analysis and filtering when they see a DDoS attack. But asking a human to monitor the edge of the network and intervene when they think they’ve spotted a DDoS attack is very labour intensive and won’t react fast enough to the automated attacks of today. Furthermore this won’t apprehend the sub-saturation attacks that experiment on your networks undetected, finding vulnerabilities and testing new methods.
So a proper modern method is one that’s always on, deployed in-line and doesn’t require human intervention in order to maintain clean traffic. The technology, whilst relatively new, is available on premises and from upstream prviders, so there are options open to most organisations no matter their size, budget and likelihood of being targeted. It also frees up your manpower to focus on preventing data exfiltration and other malicious activity taking place, making your staff much mroe productive.
So there you have it – maybe the three little pigs don’t need to worry about the big bad botnet after all! There’s methods on offer to help you build your proverbial “house” (security infrastructure) out of bricks and mitigate the most serious botnet-driven DDoS attacks on their networks.
Dave Larson is Chief Operating Officer at Corero Network Security. To find out more about Corero, head over to their website or follow them on twitter.