BEIJING -- Chinese users of Microsoft's Outlook email service were subject to a hacking attack over the weekend, just weeks after Google's Gmail service was blocked in China, an online censorship watchdog said on Monday. People using email clients like Outlook, Mozilla's Thunderbird and apps on their phone with the SMTP and IMAP email protocols, which are used to send and receive messages, around Saturday were subject to a "man-in-the-middle" (MITM) attack, said China-based GreatFire.org. A MITM attack hijacks an online connection to monitor and sometimes control communications made through that channel. Attacks and blocks on foreign Internet services have become increasingly common with China, which operates the world's most sophisticated online censorship mechanism, known as the Great Firewall, to eliminate any signs of dissent or challenges to the ruling Communist Party.
GreatFire.org said Monday that China's official Cyberspace Administration of China (CAC) was likely responsible for the MITM attack on Outlook. "If our accusation is correct, this new attack signals that the Chinese authorities are intent on further cracking down on communication methods that they cannot readily monitor," GreatFire.org said on its website. A Microsoft spokesperson said in a statement to NBC News: "We are aware of a small number of customers impacted by malicious routing to a server impersonating Outlook.com. If a customer sees a certificate warning, they should contact their Internet service provider for assistance."
Last month, Google's Gmail service was shut down in China before resuming infrequent and heavily disrupted activity, forcing many Chinese users to adopt domestic email systems.
- You Have No New Messages: Google's Gmail Service Blocked in China
- Chinese Government Agents Pay Mystery Visit to Microsoft Offices