The appearance of my BOA bookmark on my Firefox browser changed appearance. This is disturbing and frightening. I rely on that bookmark to access my finances.

My BOA bookmark on my Firefox browser changed appearance. My BOA bookmark is one I downloaded only once I was in my BOA account and felt very certain of its authenticity. This is disturbing and frightening. I rely on that bookmark to access my finances. Did Firefox do this? I just contacted BOA and they said they did not do this. They said you most likely did this. Why would you do this? This makes me feel I would be logging into a scam site if I click on it. Why would you change the appearance of a crucial to ME site like this?