im no security expert, however these things do interest me, so my explanation may get corrected by someone else here.
Essentially, if you happen to google one of these compromised sites, using google chrome as your browser, you pc will be attacked by a nasty. I have no idea what the nasty will do, likely it will be a trojan type and allow someone remote control of your pc. I also have no idea whether your internet security will pick it up, in my case a symantec business version did, whereas norton, and also bitdefender, didn't. however, malwarebytes pro did protect me on both personal pcs i tried it with
i couldn't replicate it using Microsoft edge as my browser, and google as my search engine, therefore i the nasty is targeting chrome as opposed to just the google search engine
Up until recently, malware has mainly infected pc's via infected adverts. That means that to get infected you had to be on an actual website that had a nasty advert appear as you were using it. This new attack changes the game significantly