A Chinese Bitcoin trader, helped by Web security firm Incapsula, weathered a ferocious denial-of-service attack last month when the volume of inbound traffic to the site peaked at 100Gbps.

BTC China, a platform where both Bitcoin and Chinese yuan are traded, saw an attack that lasted nine hours and was reported as one of the most fierce on record.

DNS reflection attacks involve sending a request for a large DNS zone file to a DNS server, with the details of the request forged so that they appear to come from the IP addresses of the intended victim. Only open public-facing DNS servers respond to spoofed requests which was still enough to make the tactic viable.

According to Incapsula, the attack meant that the unknown assailants had a huge amount of bandwidth at their disposal. "This amount of fire power isn't cheap, or readily available, signifying a big step up in resources pulled together to launch this type of attack."

"Even if your network provider has enough bandwidth to keep your site up, DDoS attacks not only suffocate your resources, but your neighbours as well. If you're too noisy, you may be evicted (dropped by your service provider)," it warns.