Sim boxes new tool in scammers' arsenal

AHMEDABAD: Scamsters have come up with a new method to dupe mobile network companies by using a device called the sim box to not just make international calls look like local calls but also to commit fraud and smishing scams.
The telecom industry has now recognized sim boxes as an emerging menace for law-enforcement. In four instances in Ahmedabad, city police and the department of telecom (DoT) came across the use of sim boxes.

In September 2020, police arrested two youths on the Sabarmati riverfront with a portable sim box that did not need a leased line. They had installed it on their scooter and were making spam calls.

A sim box has 20 to 500 sim card slots as part of a voice over internet protocol (VoIP) gateway. It allows the operator to bypass international rates charged by mobile network operators by converting international VoIP calls to local GSM calls. "If a person's call from London is routed through a sim box, you will see a Gujarat CLI code beginning with '98250...' instead of a '+44' UK code. The only way to track such boxes is when customers report numbers," said a police officer.

Phishing, smishing (SMS phishing) and vishing (voice phishing) are three ways a scammer might contact you to obtain information or bank credentials and carry out identity fraud. Phishing uses an email with links to collect that information, while smishing uses an SMS text sent to your phone. A sim box can be used to route thousands of international calls each day and they are difficult to trace. It can also broadcast many SMSes at one go. "Criminals also use the device to replace the international mobile equipment identity (IMEI) numbers of handsets with temporary numbers," a senior CID crime official told TOI.
DoT's director for Gujarat LSA, Sumit Mishra, said, "We have come across three major instances in Gujarat where sim boxes were used. We seek public support to report such numbers on our helpline at 1800 11 0420. The fraud detection unit of telecom service providers keep track of sim cards that make an exceptionally high number of outgoing than incoming calls. Most of these fraudulent numbers remain stationary, indicating a sim box in use. Once the mobile tower is located, the police raid the spot where the illegal exchange has been set up. "