Thai authorities announced last week the arrests of two organized fraud gangs, one of which was accused of driving through the streets of Bangkok while blasting hundreds of thousands of malicious SMS text messages to nearby cellphones. This so-called “SMS blasting” attack relies on using technology that impersonates cellular base stations, and are capable of transmitting thousands of messages to devices within a close geographical radius.

According to local news outlet Khaosod, the cellular base station setup included an 8,000-watt mobile power station, a Wi-Fi router, and four mobile phones. The gang reportedly sent close to 1 million malicious SMS text messages over a three-day period in mid-November. The news outlet reported that the messages were designed to trick recipients into thinking they had won a free gift. These attacks can be used to trick recipients into tapping on a malicious link aimed at stealing their passwords, or downloading malware.