Things like this seem "unlikely until they actually happen", then hindsight is 20/20. Enron was a public company with genuine audits, and many people were surprised it was a giant pump and dump scam.
Enron (2001): Enron Corporation, an energy company based in Houston, Texas, infamously collapsed in 2001 due to one of the most notorious cases of corporate fraud in history. Through complex accounting maneuvers and deceptive practices, Enron misrepresented its financial health, hiding debt and inflating profits.
WorldCom (2002): WorldCom was a telecommunications company that engaged in accounting fraud, inflating its assets by over $11 billion. The fraud involved improperly classifying expenses as capital investments, misleading investors and lenders. The scandal led to WorldCom filing for bankruptcy, and several executives were convicted, including CEO Bernard Ebbers.
Tyco International (2002): Tyco International, a multinational manufacturing company, was involved in a series of accounting frauds. The company's CEO, Dennis Kozlowski, and CFO, Mark Swartz, were found guilty of embezzling millions of dollars through unauthorized compensation and unauthorized stock sales. They used various fraudulent methods to conceal their activities.
HealthSouth (2003): HealthSouth, a provider of outpatient surgery, diagnostic imaging, and rehabilitation services, was involved in a massive accounting scandal. The CEO, Richard Scrushy, orchestrated a scheme to overstate the company's earnings by nearly $3 billion, inflating assets and revenues. Scrushy was eventually convicted of bribery, mail fraud, and other charges.
Lehman Brothers (2008): Lehman Brothers, a global financial services firm, played a significant role in the 2008 financial crisis. The company employed accounting practices known as "Repo 105," which involved temporarily moving assets off-balance sheet to hide its financial situation. This misleading presentation contributed to investors' false perception of Lehman Brothers' stability before its collapse.