Eric Grosse posted the following to Google’s blog today:
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Through the strength of our cloud-based security and abuse detection systems*, we recently uncovered a campaign to collect user passwords, likely through phishing. This campaign, which appears to originate from Jinan, China, affected what seem to be the personal Gmail accounts of hundreds of users including, among others, senior U.S. government officials, Chinese political activists, officials in several Asian countries (predominantly South Korea), military personnel and journalists.
The goal of this effort seems to have been to monitor the contents of these users’ emails, with the perpetrators apparently using stolen passwords to change peoples’ forwarding and delegation settings. (Gmail enables you to forward your emails automatically, as well as grant others access to your account.)
Google detected and has disrupted this campaign to take users’ passwords and monitor their emails. We have notified victims and secured their accounts. In addition, we have notified relevant government authorities.
It’s important to stress that our internal systems have not been affected—these account hijackings were not the result of a security problem with Gmail itself. But we believe that being open about these security issues helps users better protect their information online.
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If you use Gmail, do see their advice/instructions in the blog to secure your account.