Suddenly received a text message claiming to be a classmate.

Suddenly received a text message from a friend, but the phone number is a strange number, which may be one of the following situations:

1. Fraudulent information: Some scammers will use their friends' names to obtain personal information and then cheat. They usually send text messages or phone calls in the name of friends to defraud money or personal information.

2. Mass SMS: Sometimes, friends may send messages through the mass SMS function, but for some reasons, this number may not be included in your contact list correctly.

3. New friend: If this friend just met recently, they may add your number to their contact list in some way, so you received their message.

4. Wrong sending: Sometimes, friends may send short messages by mistake for some reasons, such as losing their mobile phones or borrowing them.

5. Computer virus: Some hackers may spread viruses or malware by sending short messages from friends. If you doubt the authenticity of the message, don't click on the link or attachment and contact the police immediately.

The best way is to reply to short messages and ask your friends the truth. If friends say they didn't send text messages, then you should be vigilant, don't trust the content of text messages easily, and pay attention to protecting personal information and property safety.