You could arguably call the 2008 meltdown the largest cyberheist. I can't find that article again but gosh was it great, an interview with a programmer who said

You could arguably call the 2008 meltdown the largest cyberheist. I can't find that article again but gosh was it great, an interview with a programmer who said about CDS something like we fed offal into a grinder and got steak out.