Classic auditing is intended to uncover deviations and variances from accounting standards of acceptable practice. Its focus is on the present, whereas fraud auditing concentrates on the past and future. The usual method of employee theft, fraud, and embezzlement involves the creation of a 'fake debit;' other techniques involve overstating assets and understating liabilities for balance sheet 'window dressing,' overstating sales or closing inventories, or understating expenses and returned sales. Criminals come from all social and economic strata. They have one common motive: personal enrichment at the expense of others. Other motivations are ideological, egocentric, and psychotic and may result from inadequate internal or external controls. A fraud auditor must first develop a fraud scenario, predicated on an analysis of the system's strengths and weaknesses. Next an audit plan should next be developed, which delineates the areas on which the audit focuses. Auditing for fraud is more an intuitive process than a formal analytical method. Skill depends on the abilities to think like a thief and to probe for weaknesses and also on practice. Corporate frauds can be classified into two broad categories: (1) those frauds or crimes which are directed against the company and (2) frauds or crimes which benefit the company. Crimes against the company include input scams, (i.e., phony vendor voices, payroll manipulations, thruput scams (bypassing system and programing controls) and output scams, (destroying exceptions reports, stealing files). Crimes for the company involve smoothing profits, balance sheet window dressing, pricefixing, cheating customers, violating Government regulations, corruption of customers and political corruption, and padding costs on Government contracts. Definitions of specific corporate crimes and two case studies are included.