1847453098.rsc.cdn77.org is a malicious domain, in fact. It is even detected on VirusTotal as malicious, which is not surprising though. The domain is actively involved in presenting a lot of scary alerts through infected browser. This kind of infection is called adware, but there are other side effects related to its presence. One of them is occurrence of massive scary alerts, such as this 1847453098.rsc.cdn77.org warning.