I wouldn't be at all surprised if it was actually Yobit or their staff doing this on the side - such is their reputation. Looking up yobithelp.net reveals the following:
Registry Domain ID: 2288185080_DOMAIN_NET-VRSN
Registrar WHOIS Server: whois.ionos.com
Registrar URL: http://ionos.com
Updated Date: 2018-10-26T04:08:14.000Z
Creation Date: 2018-07-21T14:45:02.000Z
Registrar Registration Expiration Date: 2019-07-21T14:45:02.000Z
Registrar: 1&1 IONOS SE
Registrar IANA ID: 83
Registrar Abuse Contact Email:
Registrar Abuse Contact Phone: +1.8774612631
Reseller:
Domain Status: ok https://www.icann.org/epp#ok
Registry Registrant ID: REDACTED FOR PRIVACY
Registrant Name: REDACTED FOR PRIVACY
Registrant Organization:
Registrant Street: REDACTED FOR PRIVACY
Registrant City: REDACTED FOR PRIVACY
Registrant State/Province: OY
Registrant Postal Code: REDACTED FOR PRIVACY
Registrant Country: NG
Registrant Phone: REDACTED FOR PRIVACY
Registrant Phone Ext:
Registrant Fax: REDACTED FOR PRIVACY
Registrant Fax Ext:
Registrant Email:
https://whois.domaintools.com/yobithelp.net
It's a different domain from the Russian one Yobit use, but it's easy enough for them to have created this domain with ionis.com & they have all Yobit users account details anyway.
Just a thought. It wouldn't surprise me at all.
Best option would be to report the domain, which Yobit could & should have done straight away, but haven't - strangely......
You have a very good point if this domain will ruin their reputation I mean adding more bad reputations to their exchange, they would have reported it right away, but it seems one of Yobit's head might be behind this or somebody that got all of the user's info in their database and now are trying to scam people, best advice is, stay from anything yobit.