I wonder if your compromised? Are you using an unsafe OS like windows?
No OS is safe from malware or spyware. It is a myth that using Linux or iOS will make your machine secure. Nowadays people are making the same mistake with ransomware.
From what I know Xapo is using CloudFlare, there was security leak discovered week ago. It was possible to sniff 'secure data' from every CloudFlare protected service.
I bet either this is a problem or your machine was compromised somehow.