[my laptop was infected]

Because you can set the laptop to shut down or remain in stand-by.

[my laptop was infected]

how did they finish the laptop? Just cover down or did you click shut down?

[I am using Windows10 `s Defender with iobit malware fighter..free]

Windows Defender is not security, especially since it sees harmless programs as a threat and microsoft wants to keep it that way, 
of course you should always keep an eye on it. Especially since the system sees the install as admin, so you have admin rights when you install it.
I don't think that many users change the user account, so it's easier to install something.

[Send Your Feedback for Advanced SystemCare 16]

Hello everyone.
I would like to give my feedback here.
I think the software is great, but the driver booster should be integrated. I wouldn't mind putting a few more bills on the table.