What can a virus do to your computer?

It can do a multitude of things, all harmful. Many viruses, which disguise themselves as tracking cookies, are meant to allow access to personal information that you give out over the internet. If you are shopping and this happens, it can be used for identity theft. Viruses can also slow down your computer significantly, erase information, destroy vital data, even shut down your computer, but those are rather extreme ones and pretty rare.some viruses encrypt themselves in a different every every time so it is impossible to
find them using anti-virus as anti-virus uses a signature string to locate them