my custom hostname (cloudflare for saas) returns "androxgh0st"? A malware?

curl -ii https://www.pagebrew.co/                                             
HTTP/1.1 200 Connection established

HTTP/2 200
(headers...)

0x%5B%5D=androxgh0st%

curl -ii https://www.pagebrew.co/                                             
HTTP/1.1 200 Connection established

HTTP/2 200
(headers...)

0x%5B%5D=androxgh0st%