sawiosl-f51a2[.]web[.]app

The domain sawiosl-f51a2.web.app was registered through Google LLC on January 09, 2019 and is hosted on a Fastly infrastructure (AS54113) located in the United States, resolving to IP address 199.36.158.100. The site presented a page title of "Swisscom Login" and was classified as a credential phishing campaign targeting Swisscom customers. It employed Google Trust Services / WR4 SSL certificates, indicating a valid TLS chain, and leveraged Firebase as the backend platform. Network analysis shows the presence of HTTP Strict Transport Security (HSTS) and support for HTTP/3, suggesting modern web delivery techniques.

The authoritative nameservers listed are ns1.googledomains.com, ns2.googledomains.com, ns3.googledomains.com, and ns4.googledomains.com. At the time of observation the HTTP response returned a 404 status, and the domain has since been taken offline. Threat intelligence platforms recorded 15 of 93 VirusTotal scanners flagging the domain as malicious, and it appears on a single security blocklist.

PhishDestroy has also blocked the domain. Defenders should ensure the domain is denied at perimeter and DNS filtering layers, monitor for any resurgence of the same hosting fingerprint or similar Firebase‑based phishing sites, and consider adding the IP address 199.36.158.100 to blocklists. Continued vigilance is advised for any future campaigns that reuse the same registrar, certificate authority, or hosting provider, as the infrastructure choices are common among credential‑phishing operations.