I've had an experience with Ana too in my server, but all 'she' did was run around using her spray can and that's it, nothing special.
I banned her shortly after when she wouldn't respond to my messages and I did obviously find out she was a bot. The owner of this account has probably started all of this so he can scare and confuse people, but that's my perspective. I also remember another bot almost identical to Ana, minus the avatar, but I can't seem to remember his name.