The amount of spam pumping out of China has dropped dramatically in the first three months of 2007, according to security experts.
A year ago, computers in China were sending out 21.1% of all spam messages, but that number has steadily fallen over the past year, totalling just 7.5% in the most recent quarter, security firm Sophos said.
During the first seven days of 2007, China accounted for just 1.7% of spam messages – n unusually sharp drop, said Carole Theriault, a senior security consultant with Sophos. "We saw a really significant drop in China at the beginning of this term. It's almost as if some ISPs were taken offline."
The sudden drop was probably caused by two major earthquakes off the coast of Taiwan, which damaged underwater data cables and disrupted internet access in Asia, Theriault said.
But a Chinese crackdown on spam should also be credited, she added. "China has been working to reduce its spam for some time now, and I think there is evidence that they have been successful."
But spammers in several European countries are making up for the fall in spam from Asia, with 5% of the world's spam for the first quarter of 2007 traced to computers connected to a single Polish internet service provider, Theriault said. She declined to name the company.
Poland now accounts for 7.4% of worldwide spam, nearly as much as China. The US, Italy, France, Germany and Spain are also included in the Sophos "Dirty Dozen" list of countries hosting top spammers.
More than 23% of all spam last year came from the US, but the percentage fell in the last quarter, to 19.8%, Theriault said.