Concerned About Potential Virus on Mac from DMG

Hi,

I was trying to download a program to my MacBook and clicked on the DMG file I believed to be the program I wanted. It then prompted one of those screens with a message like ‘double click the icon to install’ which I then did, but this prompted something called 7zip and what said it was a flash installer. I immediately realised this was not the program I was trying to install so closed down all of the windows that had popped up and deleted the DMG file it originally came from.

I’m now really worried that perhaps my MacBook now has a virus on it and was wondering if there was any advice or if it is even possible to get a virus this way.

If it makes any difference Terminal also popped up at the same time as this Installer.

Please help!