By Chris Somers
The internet was slowed worldwide last week following a cyber attack of unprecedented magnitude.
The slowdown was the result of an attack on Spamhaus, an international organisation based in London that offers spam filtering services. The attack was launched by the Dutch website hosting organisation Cyberbunker after it was listed on Spamhaus’s register of ‘unwelcome’ websites.
In what was reportedly an act of retaliation, Cyberbunker mounted a cyber-assault using the enlisted help of hackers associated with a number of European gangs, combining the power of composite ‘botnets’ of multiple computers, and also utilising home and business broadband routers.
The perpetrators employed a tactic known as Distributed Denial of Service (DDoS), which involves flooding the target servers with communications traffic in an attempt to prevent a server from being able responding to legitimate traffic, essentially rendering disconnected from the worldwide web.
This attack was unlike a conventional DDoS in its utilisation of the internet’s DNS (domain name system) servers. The hackers submitted a damaging number of requests to these servers using Spamhaus’s identity, meaning that the organisation received a substantial volume of replies from the DNS servers.
The onslaught of traffic was of a volume far greater than any attack of this kind previously seen. Large-scale, professionally organised DDoS attacks usually occur at around 50 Gbps (gigabits per second), with the previous record for the most intense episode being 100 Gbps in 2010. According to Spamhaus the requests being received during the course of last week peaked at an astonishing 300 Gbps.
Home internet routers around the world, and especially in the UK, were being used by the hackers to redirect traffic to Spamhaus’s servers, making use of the tendency of such routers to be configured to allow remote control for purposes such as maintenance.
The sheer scale of this attack led to a knock-on effect for internet speeds around the globe. The volume of traffic being launched led to a phenomenon being described as similar to a congested motorway.
Photograph: Christian Haugen