The domain name gcr.io is owned by Google, and used for its cloud storage solutions. WhoIs registry details for this domain can be found here.
gcr.iohosts images in data centers in the United States, but the location may change in the future
us.gcr.iohosts image in data centers in the United States, in a separate storage bucket from images hosted by
eu.gcr.iohosts the images in the European Union
asia.gcr.iohosts images in data centers in Asia
The GCR stands for Google Container Registry.
This domain is safe and has not been known to host malware or other malicious content.