Kim Zetter:

Scrooge lurks on the ATM quietly in the background until someone wakes it up in person. It can be initiated in two ways — either through a touch-sequence entered on the ATM’s keypad or by inserting a special control card. Both methods activate a hidden menu an attacker can use to make the machine spew out money or print receipts. Scrooge will also capture magstripe data embedded in bank cards other users insert into the ATM.

They received bonus points for the name ‘scrooge’.