Here is a scam someone tried to pull on us a while back. It's called the officers alt banker scam.
Someone takes a look at the guild roster so see who the top officers are. They then create an alt with a name like on of those but sounds like a banker or an auction character. Kevbank is the name they tried. They waited for me to log off or they did not see me online. They would whisper all the high ranking officers asking for an invite.
Once invited they would ask to be promoted for guild bank access. Once promoted they would withdraw as much as they could before someone figured it out. I think that's how the scam should work. Like I said, this is a scam someone tried to pull.
He failed for several reasons. Most officers knew who my banker was and that was not it. The average age of our members is higher then most guild so the words he used put him way younger. I don't use the word "dude" when talking to people. I was also on an out of guild alt that one officer knew about. So he sent me a whisper shortly after it was attempted. I was able to log onto my main and tell them it was not me if anyone had any questions.
I point this out as something you should mention to your officers. So they think twice when inviting and promoting that alt. I had a mega guild once get very mad at me because officers would keep inviting me in. The guild was so big that one set of officers would gkick me on the spot and another set would invite me with out knowing they shouldn't.