The attack was the largest of its kind ever in China, according to the China Internet Network Information Center, a state agency that manages the .cn country domain.
The double-barreled attacks took place at around 2 a.m. Sunday, and then again at 4 a.m. The second attack was "long-lasting and large-scale," according to state media, which said that service was slowly being restored.
Official state media said the attack targeted websites with the .cn country domain, as well as the popular microblogging site Sina Weibo.
Denial of service attacks aren't technically "hacks," since they can be done without breaking into any systems. Typically, DoS attacks overwhelm a website's servers by flooding them with requests. That makes websites unreachable or unresponsive.
To bring down bigger sites, attackers will sometimes organize large numbers of infected computers to send requests all at once. Read more >>