Cloud-based web hosting company hit by two-week-long DDoS attack

Linode is a cloud-based provider of web-hosting to over 400,000 clients. Yesterday it advised all customers that it was resetting passwords due to a suspected data breach. That sounds like a standard response to a security issue, however the company added that it has been under a sustained DDoS attack for the past two weeks. In a detailed account of the ongoing attack, one of the company's network engineers explained that over the first six days the company suffered 30 different attacks that changed vectors every time the company plugged a vulnerability. Typically, a DDoS attack will last for a number of hours aiming to saturate and essentially disable the target's systems, often as a smoke-smokescreen for inserting malware of some sort; yet this prolonged attack, switching from vector to vector, seems to be a new and highly sophisticated variant.

It all started on Dec. 26: Cloud hosting provider Linode reported a series of DDoS attacks affecting its Linode Manager and website, according to SecurityWeek. Infrastructure was also targeted, but in a few hours, the company’s IT teams had everything under control.

Until the next day. So began a 10-day series of continuing attacks that left most of Linode’s services slow or unresponsive. The company has since resolved these issues, but is it possible to mitigate this kind of DDoS damage going forward, or are cloud providers forever at the mercy of denial-based storms?

Common Theme

The distributed denial-of-service (DDoS) attack is a common vector for cybercriminals since it’s often the easiest means to an end: Malicious actors compromise a large number of devices, then have them all attempt simultaneous, high-traffic connections. Targeted servers may slow to a crawl as CPUs attempt to keep up or fail altogether if overwhelmed.

In some cases, the threat of DDoS attacks are used to compel action or demonstrate security weakness. For example, the hacking group Phantom Squad threatened to take down the PSN and Xbox Live gaming networks on Christmas to showcase poor IT security practices. While there were some minor service hiccups during the holidays, it seems the group was either unsuccessful or simply chose a new target. Linode, unfortunately, did not fare so well.

A Poor Present

As noted by SC Magazine, the Christmas attacks on Linode caused “service interruptions at DNS infrastructure and data center locations in the U.S. and the U.K., including Dallas, London, Atlanta, Frankfurt, Newark, N.J., Tokyo, Singapore and Fremont, Calif.” What’s more, they occurred just after maintenance on Xen Linode host servers and came with no warning. No group has stepped forward to claim responsibility or demand any kind of action from the cloud provider.

Instead, the company was hit by attack after attack and was criticized for a lack of response to the issue at hand. By New Year’s Eve, Linode network engineer Alex Forster posted a detailed article about the hack, noting that in six days, the company had endured 30 different attacks that switched vectors each time Linode closed a security hole. According to The Register, as of Jan. 4, the cloud provider was finally back on track, with only one server in Atlanta listing a partial outage.

Takeaways From the DDoS Attacks

For cloud providers, the Linode attack is an uncomfortable reminder that the massive attack surface presented by servers and infrastructure makes cloud offerings a tempting target for DDoS attacks. Sheer request volume can quickly overwhelm even high-traffic servers, and the results are often unpredictable. As problems spread from the back end to specific tenants, they spill over into other client instances, turning a complex situation into complete chaos.

Best bet? Linode offers a good example: Hunker down and start closing holes. While this is no guarantee that attackers will shut things down and walk away, it’s often the quickest and most effective way to mitigate the impact of distributed attacks. As Forster’s blog post demonstrated, however, companies can’t afford to ignore their public face even when fighting private battles. Whenever possible, it’s important to provide a kind of play-by-play — an active report on what’s happening and what’s being done to counter the issue.

Short and sweet? No company is immune to DDoS attacks, and in the cloud, these storms have far-reaching impacts.