1. virus database scanning technology: by scanning files in a computer system, the characteristics of known viruses are compared with those in the virus database, and once a match is found, whether the file is a virus can be judged.

2. Signature identification technology: similar to virus database scanning technology, the difference is that signature identification technology is aimed at identifying the characteristics of a specific virus, not the entire virus database.

3. Behavior monitoring technology: By monitoring the behavior of the computer system, once abnormal behavior is found, it will immediately alarm or isolate.