It is unclear whether the attacks on the other major email services came from China, as well.
Google contained the phishing campaign, accounts had their security beefed up and the authorities were notified.
The attacks on Hotmail and Yahoo! Mail showed "significant similarities," to the Google attacks, notes Trend Micro in its report.
While the attack on Yahoo seemed a run-of-the-mill attack to steal cookies, the Hotmail attack was much more malicious.
Says Trend (via IBT):
Unlike other email-based attacks that require users to open the message and to click an embedded link or to download and execute an attachment, this attack's execution merely requires users to preview the message in their browsers.