Doubt

"Why is there no signal on my mobile phone? Why can't I call? I can't send messages either." At this moment, someone realized that he could neither make calls nor send messages on his mobile phone.

"I can't get online with my phone." Then, someone realized that he couldn't go online with his mobile phone.

"What's wrong with my mobile phone? I can't open the photo album and the documents."

"Oh my god, my mobile phone seems to be infected too!" Someone tried to open the photo album and documents. A window popped up requesting a virtual currency ransom within a deadline.

If the ransom wasn't paid on time, all the information in his phone would be deleted and couldn't be restored.

Some people had very important documents saved on their phones, and sweat broke out on their foreheads.

"Everyone, please be quiet!" Principal Wu said solemnly.

"I just received news that a Doomsday Extortion Virus invasion has occurred worldwide."