What's going on here? I received a short message saying that my Nokia N8 1 has a major security risk.

Congratulations, you've been cheated. It seems that the symptom should be the virus "evolution" of the recently popular botnet. Its scientific name is FC.ThemeInstaller.A After installation, users will secretly send short messages of this kind of content after locking the screen, and will automatically connect to the Internet, and will also collect private information from your mobile phone for uploading. In short, it is BT. Kill it quickly. This virus was first broadcast by netqin and should be able to be killed.