macOs infected with JS.Cryptonight (Trj)

[michel52]

hello everyone,
i have a problem with my iMac , he is infected with a trojan virus called Js.Cryptonight (Trj) and i can't get remove it from my macOs high sierra !
i have Avast security as antivirus protection and avast finds always the virus and i can remove it but when i scan again its there again ... even malwarebytes can't find the virus!
also bitdefender can't find anything , only avast and and right its spreads through my macOs high sierra

How can i fix this problem?

 

[Rok73]

Is there a possibility that it's a false positive?

 

[michel52]

yes it could be ... but i am not shure