Why do I log in to QQ, one needs a verification code and the other doesn't?

QQ number mainly has two numbers (that is, two people know that the number password is used in different places at different times), which is not easy to be found by the original number owner, so we introduce the verification code to attract the attention of the real number owner and reduce the loss of the original number owner. I hope everyone can strengthen the awareness of number prevention and create a green and healthy online environment. Now list the specific reasons and solutions:

Specific reasons:

1. Send advertisements or scam messages: Some users report your number to send advertisements or scam messages. If it weren't for your behavior, the password of your number might have been known by others and used to send advertisements or scam messages without your knowledge.

2. Log in from different places

That is, your number often logs into a place, and suddenly it is detected that the place where you log in has changed. For security reasons, a verification code will be added.

3, the number has a hang-up behavior: usually hackers will use the help of the user to hang up to steal the user's property and number.

Solution:

1. Change the password immediately after finding the verification code, and kill the Trojan horse.

2. After the verification code is needed, enter the observation period. After normal use of 10 ~ 20 days, the system will automatically cancel;

If you think my answer is satisfactory, please give me full marks. Thank you.