What Actually happens
These boys were looking for the ATM's manual on the internet, and they got the operator's manual for the BMO ATM. With the help of reading the manual, they were able to switch the ATM machine over to administrator mode by simply entering one of the default system passwords. And that allows them to do number of the task over the ATM machine.
When the default password works for them, which allow them to enter to the Administrator mode of the ATM's, they have reported the security loopholes to employees at a local BMO branch. The extent of the damage they did was changing the ATM's welcome screen to read "Go away. This ATM has been hacked."
They have submitted all the printed documents at a local BMO branch, and this time bank staff have notified the issue to the branch manager. Further the issue was reported to the security head of the BMO bank.
Header Image Credit:- Gizmodo.com