India, April 1 -- The Central Bureau of Investigation (CBI) has launched a probe into a cyber-fraud network that allegedly used bulk, fraudulently obtained SIM cards to target thousands of individuals across the country. The Bihar Police initially probed the case, which the CBI recently took over due to the involvement of accused from other states.

According to CBI, the network employed a sophisticated setup involving SIM boxes to convert Voice-over Internet Protocol (VoIP) calls into local calls, thereby masking their origin and bypassing security checks. Using this method, the accused allegedly made over 15,000 calls across India within a fortnight between June and July 2025 from a base in Bihar's Supaul district.

A SIM box routes int...