test.user.js

const regex = /\.profile_view_img_(.*?) { background-image: url\('https:\/\/www\.like4like\.org\/img\/(.*?)'\);/g;
const str = document.body.innerHTML;
let m;

while ((m = regex.exec(str)) !== null) {
    // This is necessary to avoid infinite loops with zero-width matches
    if (m.index === regex.lastIndex) {
        regex.lastIndex++;
    }
    
    // The result can be accessed through the `m`-variable.
    m.forEach((match, groupIndex) => {
        console.log(`Found match, group ${groupIndex}: ${match}`);
    });
}