If QQ messages sent by strangers are returned, will they be infected with viruses?

No, you can't catch the virus with a simple reply. Only receive other software. Or open a webpage connection sent by the other party. , it is possible to get the virus.

Computer virus is a set of computer instructions or program codes that a compiler inserts into a computer program to destroy computer functions or data, which can affect the use of the computer and replicate itself.

Computer viruses are contagious, hidden, contagious, latent, exciting, expressive or destructive. Life cycle of computer virus: development period → infection period → incubation period → attack period → discovery period → digestion period → extinction period.

A computer virus is a program, an executable code. Just like biological virus, it has the characteristics of self-replication, mutual infection and activation and regeneration. Computer virus has unique replication ability. They can spread quickly and are usually difficult to eradicate. They can attach themselves to various types of files, and when files are copied or transmitted from one user to another, they will spread with the files.