People use their mobile phones outside a government office in Makati on April 24, 2023. Jonathan Cellona, ABS-CBN News/File

MANILA — The Department of Information and Communications Technology (DICT) on Wednesday warned that IMSI (International Mobile Subscriber Identity) catchers could be operating in public spaces, tracking and intercepting mobile phone communications.

The device, also known as a “stingray,” rogue cell tower, fake cell tower, cell site simulator, or drop box, works by mimicking a legitimate cell tower and convincing nearby phones to connect to it.

Philippines arrests Malaysian tagged in text scams

Once connected, it can collect the IMSI numbers of devices, enabling it to track their location and activity, as well as intercept text messages, calls, and data traffic.

The IMSI catcher, which can be used for mass SMS broadcasting without needing a database, SIM card, or WiFi, is often used in text scams.

On Tuesday, the Philippine National Police-Anti-Cybercrime Group (PNP-ACG) arrested a 46-year-old Malaysian man, believed to be the head of a syndicate supplying IMSI catchers for illicit activities.

“Sigurado. Sigurado, may nabentahan na ‘yan,” said DICT Secretary Ivan Uy in a media briefing at Camp Crame. (For sure. For sure, he has already sold some of them.)

He added that the device costs around P600,000.

Uy said IMSI catchers could be used during elections for text blasts, giving candidates an advantage by reaching a larger audience.

“In the past elections, nakita natin na ginagamit itong IMSI catcher for text blasting. At dati, napakamabenta nitong mga equipment na ito sa mga politicians, especially for election purposes. So, tumataas ang bentahan nito tuwing eleksyon,” he said.

(In the past elections, we’ve seen that this IMSI catcher was used for text blasting. And before, these devices were very popular among politicians, especially for election purposes. So, the price goes up during election time.)

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Uy advised the public to stay alert and report any suspicious activity, such as individuals wearing backpacks and pacing back and forth, or vehicles repeatedly circling an area.

“This is very concerning. Posibleng may kasabwat na mga local. Nakita niyo the other day, may nahuling espiya. Hindi sila makapag-operate. Kailangan may kasabwat silang mga taga Pilipinas na alam kung paano gumalaw dito,” he said.

(This is very concerning. It’s possible there are local accomplices. You saw the other day, an espionage agent was arrested. They couldn’t operate without local accomplices in the Philippines who know how to move around here.)

Uy said authorities will also trace those who purchased the device in the country.

“Our best advice is for you to surrender the device voluntarily. Surrender it because we have already caught the supplier, so it’s just a matter of time before we find out who bought it. Once we know, we will go after you.” he said.

(Our strongest advice is to surrender the device voluntarily. Surrender it now, because we've already caught the supplier. It's only a matter of time before we trace who bought it, and once we do, we will come after you.)

The Malaysian suspect, who faces multiple charges, is currently in the custody of the PNP-ACG.

Philippine authorities are collaborating with the Malaysian government and will also coordinate with officials from Cambodia, China, and Thailand, where he first traveled and is suspected to have sold the devices.

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