Protecting your network from DDoS attacks starts with planning your response. Here, security experts offer their best advice for fighting back.
DDoS attacks are bigger and more ferocious than ever and can strike anyone at any time. With that in mind we’ve assembled some essential advice for protecting against DDoS attacks.
1. Have your DDoS mitigation plan ready
Organizations must try to anticipate the applications and network services adversaries will target and draft an emergency response plan to mitigate those attacks.
“Enterprises are paying more attention to these attacks and planning how they’ll respond. And they’re getting better at assembling their own internal attack information as well as the information their vendors are providing them to help fight these attacks,” says Tsantes.
IBM’s Price agrees. “Organizations are getting better at response. They’re integrating their internal applications and networking teams, and they know when the attack response needs to be escalated so that they aren’t caught off guard. So as attackers are becoming much more sophisticated, so are the financial institutions,” she says.
“A disaster recovery plan and tested procedures should also be in place in the event a business-impacting DDoS attack does occur, including good public messaging. Diversity of infrastructure both in type and geography can also help mitigate against DDoS as well as appropriate hybridization with public and private cloud,” says Day.
“Any large enterprise should start with network level protection with multiple WAN entry points and agreements with the large traffic scrubbing providers (such as Akamai or F5) to mitigate and re-route attacks before they get to your edge. No physical DDoS devices can keep up with WAN speed attacks, so they must be first scrubbed in the cloud. Make sure that your operations staff has procedures in place to easily re-route traffic for scrubbing and also fail over network devices that get saturated,” says Scott Carlson, technical fellow at BeyondTrust.
2. Make real-time adjustments
While it’s always been true that enterprises need to be able to adjust in real-time to DDoS attacks, it became increasingly so when a wave of attacks struck many in the financial services and banking industry in 2012 and 2013, including the likes of Bank of America, Capital One, Chase, Citibank, PNC Bank and Wells Fargo. These attacks were both relentless and sophisticated. “Not only were these attacks multi-vector, but the tactics changed in real time,” says Gary Sockrider, solutions architect for the Americas at Arbor Networks. The attackers would watch how sites responded, and when the site came back online, the hackers would adjust with new attack methods.
“They are resolute and they will hit you on some different port, protocol, or from a new source. Always changing tactics,” he says. “Enterprises have to be ready to be as quick and flexible as their adversaries.”
3. Enlist DDoS protection and mitigation services
John Nye, VP of cybersecurity strategy at CynergisTek explains that there are many things enterprises can do on their own to be ready to adjust for when these attacks hit, but enlisting a third-party DDoS protection service may be the most affordable route. “Monitoring can be done within the enterprise, typically in the SOC or NOC, to watch for excessive traffic and if it is sufficiently distinguishable from legitimate traffic, then it can be blocked at the web application firewalls (WAF) or with other technical solutions. While it is possible to build a more robust infrastructure that can deal with larger traffic loads, this solution is substantially costlier than using a third-party service,” Nye says.
Chris Day, chief cybersecurity officer at data center services provider Cyxtera, agrees with Nye that enterprises should consider getting specialty help. “Enterprises should work with a DDoS mitigation company and/or their network service provider to have a mitigation capability in place or at least ready to rapidly deploy in the event of an attack.”
“The number one most useful thing that an enterprise can do — if their web presence is that critical to their business — is to enlist a third-party DDoS protection service,” adds Nye. “I will not recommend any particular vendor in this case, as the best choice is circumstantial and if an enterprise is considering using such a service they should thoroughly investigate the options.”
4. Don’t rely only on perimeter defenses
Everyone we interviewed when reporting on the DDoS attacks that struck financial services firms a few years ago found that their traditional on-premises security devices — firewalls, intrusion-prevention systems, load balancers —were unable to block the attacks.
“We watched those devices failing. The lesson there is really simple: You have to have the ability to mitigate the DDoS attacks before it gets to those devices. They’re vulnerable. They’re just as vulnerable as the servers you are trying to protect,” says Sockrider, when speaking of the attacks on banks and financial services a few years ago. Part of the mitigation effort is going to have to rely on upstream network providers or managed security service providers that can interrupt attacks away from the network perimeter.
It’s especially important to mitigate attacks further upstream when you’re facing high-volume attacks.
“If your internet connection is 10GB and you receive a 100GB attack, trying to fight that at the 10GB mark is hopeless. You’ve already been slaughtered upstream,” says Sockrider.
5. Fight application-layer attacks in-line
Attacks on specific applications are generally stealthy, much lower volume and more targeted.
“They’re designed to fly under the radar so you need the protection on-premises or in the data center so that you can perform deep-packet inspection and see everything at the application layer. This is the best way to mitigate these kinds of attacks,” says Sockrider.
“Organizations will need a web protection tool that can handle application layer DoS attacks,” adds Tyler Shields, VP of Strategy, Marketing & Partnerships at Signal Sciences. “Specifically, those that allow you to configure it to meet your business logic. Network based mitigations are no longer going to suffice,” he says.
Amir Jerbi, co-founder and CTO is Aqua Security, a container security company, explains how one of the steps you can take to protect against DDoS attacks is to add redundancy to an application by deploying it on multiple public cloud providers. “This will ensure that if your application or infrastructure provider is being attacked then you can easily scale out to the next cloud deployment,” he says.
The banking industry is collaborating a little when it comes to these attacks. Everything they reveal is carefully protected and shared strictly amongst themselves, but in a limited way, banks are doing a better job at collaborating than most industries.
“They’re working among each other and with their telecommunication providers. And they’re working directly with their service providers. They have to. They can’t just work and succeed in isolation,” says Lynn Price, IBM security strategist for the financial sector.
For example, when the financial services industry was targeted, they turned to the Financial Services Information Sharing and Analysis Center for support and to share information about threats. “In some of these information-sharing meetings, the [big] banks are very open when it comes to talking about the types of attacks underway and the solutions they put into place that proved effective. In that way, the large banks have at least been talking with each other,” says Rich Bolstridge, chief strategist of financial services at Akamai Technologies.
The financial sector’s strategy is one that could and should be adopted elsewhere, regardless of industry.
7. Watch out for secondary attacks
As costly as DDoS attacks can be, they may sometimes be little more than a distraction to provide cover for an even more nefarious attack.
“DDoS can be a diversion tactic for more serious attacks coming in from another direction. Banks need to be aware that they have to not only be monitoring for and defending the DDoS attack, but they also have to have an eye on the notion that the DDoS may only be one aspect of a multifaceted attack, perhaps to steal account or other sensitive information,” Price says.
8. Stay vigilant
Although many times DDoS attacks appear to only target high profile industries and companies, research shows that’s just not accurate. With today’s interconnected digital supply-chains (every enterprise is dependent on dozens if not hundreds of suppliers online), increased online activism expressed through attacks, state sponsored attacks on industries in other nations, and the ease of which DDoS attacks can be initiated, every organization must consider themselves a target.
So be ready, and use the advice in this article as a launching point to build your organization’s own anti-DDoS strategy.