suspicious code

Hi all,

When I log onto sites, I am getting this code. Why do I get it and how do I delete it?

thanks

boomerangSaveLoadTime); } if (document.addEventListener) { document.addEventListener("onBoomerangLoaded", function(e) { e.detail.BOOMR.init({ ResourceTiming: { enabled: true, trackedResourceTypes: ["script", "img", "css"] }, }); e.detail.BOOMR.t_end = new Date().getTime(); }); } else if (document.attachEvent) { document.attachEvent("onpropertychange", function(e) { if (!e) e=event; if (e.propertyName === "onBoomerangLoaded") { e.detail.BOOMR.init({ ResourceTiming: { enabled: true, trackedResourceTypes: ["script", "img", "css"] }, }); e.detail.BOOMR.t_end = new Date().getTime(); } }); } })();