I received a short message saying that I visited a bad website.

The mobile phone received a yellow message and was really infected with the virus. If your mobile phone often receives yellow messages, it proves that your mobile phone is really infected with the virus. You must have automatically carried the virus in some software when you downloaded it.

Virus is a small and simple structure, containing only one kind of nucleic acid (DNA or RNA), which must be parasitic in living cells and reproduce through replication.