Firefox has a hidden tab with Chinese characters.
The Firefox block on the taskbar line had Chinese characters displaying the current location. I closed all of my tabs and then clicked to quit Firefox. I then got a dialog box stating that I had multiple tabs open with Save, Quite, Cancel as options. The Chinese site was some how operating on a hidden tab. I had visited only sites such as BBC, Google Search, some trusted weather sites and downloaded some PDF from sites the McAfee had flagged as Safe. Any ideas?
Opaite Mbohovái (1)
If you see CJK (Chinese/Japanese) characters on the Firefox title bar or the Windows Taskbar then that can happen if Firefox switches to UTF-16 encoding for some reason.
The "RealPlayer Browser Record Plugin" extension (Tools > Add-ons > Extensions) has been reported to cause that issue.
Be sure not to get confused with the RealPlayer plugin (Tools > Add-ons > Plugins) that plays media files. The extension adds some extra features like saving media files.
You can disable/remove the RealPlayer Browser Record Plugin extension in the RealPlayer Preferences (RealPlayer: Tools > Preferences > Download & Recording)
See also Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems