CFO OnBoarding - EFTSure

There are 3 main ways businesses get caught out

Business Email Compromise (BEC)

Rogue employee

Careless whisper

Fraudster wants to target a company... (Target Co A)
Instead of attacking Target Co A Fraudster sends phishing email to a supplier (Supplier Co B)
Employee at Supplier Co B clicks on email and logs in to a fake site
Fraudster uses details to gain access to Supplier Co B's email account
Fraudster sends finance team at Target Co Aemail informing of change in Bank details and/or an invoice with a new bank account number
Target Co A pays invoice, but money goes to Fraudster, not Supplier Co B

Connie, an employee in Accounts payable desperately needs money. So she finds a frequently paid supplier and creates and additional invoice for that supplier. This has the suppliers correct bank details.
She inserts the invoice into the ERP/Accounting system. She doesn't need to put in her banking details because she rather makes that change, in the easily editable ABA (banking file).
The bank pays according to the edited file and so the money goes to Connie. The system doesn't pick it up because it contains a 'legitimate invoice'.
It's very hard to detect this type of crime. It may be detected years later if an auditor investigated deeply.

An nefarious employee or other party gains access to the ERP or accounting system, usually through weak passwords or poor password security like employees writing it down on paper.

Once inside, they can do any number of things, such as changing the account details stored in the system or frequently paid suppliers, or even updating the company's own invoice template to include their details so that all incoming payments get diverted to them.