China is suffering from a serious attack on its computer system. Connections to many websites have been slowed or killed altogether. The source of the attack is unknown at the moment, although it is unlikely a non-Chinese government attack.

According to the South China Morning Post a massive attack began about midnight China time on Sunday and continued for several hours. The attack interfered with websites which us the most common top level domain, .cn. It is reported that the attack was far more ferocious than any previous denial of service attack, suggesting that it was preplanned and the work of a large network, not an individual hacker.

One source quoted in the SCMP article downplayed the idea that a foreign government might be behind this incident, although non-Chinese websites were involved. As the source put the matter, "Government hackers prefer sneaking in the back door, not slamming the front door."

Which leaves open the possibility that this attack could be the work of disgruntled Chinese users of their social media (their equivalent of Facebook and Twitter) who have been subject to unpopular government crackdowns. 

Whatever the source of this attack, it demonstrates that Chinese computer systems are vulnerable. The impression many Westerners have is that China is a computer systems aggressor, and the rest of the world its its victim. Perhaps China is more vulnerable than outsiders suspect.