Does Bancanet (Banamex) really have a virus?

I just tried to log into my Banamex account via https://bancanet.banamex.com/ and after entering my client number (first thing you enter) and clicking to continue, Avast stopped me with a “HTML:Script-inf[Susp]” error. How can I determine if this is a true threat or a false positive?

Interesting, could the reason its down for maintenance be why Avast was alerting, I’m not one for coincidences. :-\

Website is down for maintenance according to this (click on screenshot to enlarge)
https://urlscan.io/result/267e4406-6722-44a4-ba99-9a5865ac4d74/

How can I determine if this is a true threat or a false positive?
https://forum.avast.com/index.php?topic=14433.msg1289438#msg1289438