ICE Homeland Security Investigations executed a nationwide operation targeting illegal SIM box operations run by transnational criminal organizations between June 22 and July 10. The mission, dubbed Operation Signal Break, dismantled critical command-and-control infrastructure used to perpetrate large-scale telecommunications fraud across the United States.
Led by the DHS Cyber Crimes Center with significant assistance from HSI Los Angeles, Operation Signal Break mobilized specialized “SIM Box Surge Teams” of special agents, criminal analysts and computer forensics analysts to high-risk areas in California, Florida, Texas, Massachusetts, New York and New Jersey. The coordinated effort involved more than 11 HSI field offices.
Operation Signal Break is the latest initiative targeting illegal SIM box operations across the United States. Since 2024, HSI has executed over 116 federal criminal search warrants, seizing more than 500,000 SIM cards, over 1,900 SIM boxes, and more than $700,000 in illicit proceeds. HSI’s investigations have led to one criminal arrest, 11 administrative arrests, and the disruption of 68 SIM farms in 15 states used to facilitate fraudulent texts and calls. These actions were often coordinated across regions to prevent criminal organizations from reconfiguring their infrastructure to evade law enforcement.
“I commend our special agents for their outstanding dedication and teamwork in dismantling illicit telecommunications infrastructure. Their relentless pursuit of justice and commitment to protecting the integrity of our communications networks have made our communities safer and sends a clear message to those seeking to exploit our systems to defraud Americans,” said HSI acting Executive Associate Director John Condon. “This success is a testament to the skill and determination of our HSI team.”
SIM farms are collections of devices — known as SIM boxes — that house hundreds or thousands of cellphone SIM cards. These devices enable criminals to route massive volumes of calls and text messages over the internet, disguising the origin of communications and facilitating illegal activities such as scam calls, phishing texts and fraud schemes. These operations cost Americans an estimated $15 million each year, according to the Federal Trade Commission.
HSI Los Angeles, in partnership with the Counter Threat Finance Unit and the Cross Border Financial Crimes Center, will analyze seized SIM data and network artifacts to identify victims, quantify fraud losses, and trace illicit proceeds linked to Chinese transnational criminal organizations and their distribution networks. These results will support further criminal indictments, asset seizures, and sanctions targeting domestic and overseas infrastructure.
Operation Signal Break included HSI Los Angeles, HSI Miami, HSI Tampa, HSI New England, HSI Houston and additional offices nationwide. Significant assistance for this operation was provided by the U.S. Attorney’s office for the Central District of California.
The original announcement can be found here.
