It's either a false positive, or your computer itself is infected.
This might the reason, I use Norton and browse the site of bitmain but didn't detect any malicious malware there.
[EDIT]
I search the o7tnsxhoh.qnssl.com subdomain and the google resulted that this sud-domain and bitmain is kinda related (if I'm not mistaken).
Here's the image of some in of their layout related js. And your anti-virus might detected it as a malware coz the o7tnsxhoh.qnssl.com subdomain doesn't exist or down already.