Can answering unknown calls hack your phone?

DECODED: TECH, TRUTH, AND THREATS

By Art Samaniego

A social media post recently went viral, claiming that someone had his SIM and bank accounts hacked after answering a call from an unknown number. The story made waves. It’s the kind of thing that sticks with you, that unsettles you. A simple call, and suddenly your money’s gone?

The story may sound convincing at first, but I don’t buy the idea that simply answering a call could lead to something this serious. What it describes lines up much more closely with a SIM swap scam, something we’ve seen before.

SIM swapping involves fraudsters convincing a telco to transfer your number to their SIM card. That gives them access to your calls and texts, including one-time passwords (OTPs) from banks and other platforms. In short, your phone number becomes theirs, and they start getting your codes.

According to the viral post, the victim stopped receiving OTPs, delivery riders couldn’t reach them, yet transactions linked to their number continued to go through. That’s textbook SIM swap behavior. The call? It might have been a distraction, or a red herring.

Some have suggested that this could be a case of an IMSI catcher, a type of fake cell tower that tricks nearby phones into connecting, thereby allowing it to intercept data. An IMSI catcher is a real tool often used by law enforcement.

But for a typical scammer to deploy one, especially just to hijack a single SIM, is a stretch. IMSI catchers typically do not reassign your number, and they certainly don’t require the target to answer a call to work.

To clarify: a regular voice call can’t reprogram your SIM, install malware, or “listen “its way into your system. Calls are just audio. That’s it. The idea that staying on the line makes you more vulnerable isn’t supported by how mobile networks actually work.

That’s why viral stories like this, while attention-grabbing, can be misleading. They stir panic around unknown numbers, but overlook the more pressing issue: weak telco safeguards that allow unauthorized SIM swaps to happen in the first place.

What should concern us more is how easy it still is for someone to take control of our phone numbers. Why do banks continue to rely on SMS-based OTPs when safer methods, such as authenticator apps, are available?

The takeaway isn’t to avoid unknown numbers altogether. It’s to stay informed about real threats, advocate for better systems, and understand how these scams actually work. Because the more we buy into myths, the less prepared we are for what’s really out there.