The "STOP Scammers Act" requires the Secretary of the Treasury to designate certain foreign entities as Foreign Financial Threat Organizations (FFTOs). These organizations are defined as foreign entities, including subsidiaries or affiliates, that engage in fraudulent activities to deceive U.S. citizens or lawful permanent residents into providing cash or other assets, as jointly determined by the Secretary of the Treasury and the Attorney General. Upon designation, which must occur within 90 days of enactment, the Secretary must notify Congress and publish the designation in the Federal Register. This designation allows the Secretary to require U.S. financial institutions to freeze assets of FFTOs and subjects these organizations to the same penalties and procedures as specially designated global terrorist organizations. Furthermore, the bill authorizes the federal government to take actions to protect U.S. cybersecurity and limit FFTOs' access to internet or cellular services. It also mandates the Secretary of the Treasury to prevent FFTOs from contacting U.S. citizens or lawful permanent residents via phone, internet, or email. The act requires annual reports to Congress detailing designated organizations, seized assets, and funds returned to victims of fraud.