A “paper trail” is a series of documents that show a record of a person’s or organization’s activities. When paired with invoices, checks allow businesses to have a paper of scanned PDF record of service provided, payment sent, and payment received. This “paper trail” is essential for good financial management and record-keeping. In this case, the “paper trail” is the scanned PDF documents that record all of the business’s payments. The criminals were careful not to leave a “paper trail” of their fraudulent activities.