SIM Box scam explained as CBI seizes 21,000 SIM cards in Delhi, Noida and Chandigarh

The Central Bureau of Investigation has launched a major crackdown on a cybercrime network using SIM Box devices across Delhi, Noida and Chandigarh, highlighting how telecom loopholes are being exploited to run large-scale scams, as reported by the Times of India.

According to the report, the raids exposed an extensive phishing operation, with investigators seizing more than 21,000 illegally procured SIM cards. Officials informed that the operation revealed the scale at which cybercriminals are misusing telecom infrastructure to target unsuspecting citizens across the country.

What is a SIM Box scam

A SIM Box is a device designed to hold hundreds of SIM cards at the same time. Cybercriminals use these devices to route international calls and messages through local SIM cards, making them appear domestic and allowing them to bypass telecom regulations and charges. Authorities stated that these devices are widely used to send bulk SMS messages containing phishing links, fake loan offers and fraudulent investment schemes, making it difficult to trace the origin of the scams.

How the SIM Box scam works

Investigators said the scam typically begins with criminals acquiring thousands of SIM cards using fake or forged identities. These SIM cards are loaded into SIM Boxes connected to servers and dongles. The system is then used to send lakhs of SMS messages every day, tricking recipients into clicking malicious links or sharing sensitive banking and personal information. The CBI investigation revealed that foreign cybercriminals were also using such networks to target Indian citizens, turning the scam into a transnational threat.

Why the SIM Box scam is dangerous

Financial fraud, as victims may lose money after sharing bank or card details

Identity theft, with personal data being stolen or misused

National security concerns, since international calls disguised as local calls make tracking criminals more difficult

How to stay safe

Experts advised citizens to remain alert and take the following precautions

Avoid clicking on links in SMS messages offering loans, investments or job opportunities

Verify the sender’s number, as scam messages often originate from random or unusual numbers

Report suspicious messages to the government cybercrime portal at cybercrime.gov.in

Enable spam filters on smartphones to block bulk and suspicious SMS messages

Contact banks immediately if a scam is suspected and update passwords regularly