It might seem harmless, perhaps even accidental. But according to CyberSecurity Malaysia (CSM), that “silent call” could be the first step of a scam.

“Answering these calls might confirm your number as active, and that’s enough to land you on a target list for future scams,” said CSM chief executive officer Amirudin Abdul Wahab.

He explained that scammers sometimes use such calls to collect voice metadata. “Even if you keep quiet, the call can be recorded to identify your voice or background sounds.

“Once they know the number is active, it may be sold or used for further fraud,” he said.

A silent call typically ends less than 10 seconds after being answered. But it doesn’t always end there – victims often receive follow-up messages or calls afterwards.

“In some cases, they will get an SMS saying their bank account will be suspended unless they call a number. Others receive WhatsApp messages with fake links or job offers.

“After a few rounds of silent calls, a scammer might call again pretending to be from a bank, courier service or government agency.”

Scammers often go a step further by disguising their phone numbers to look local – a technique known as spoofing.

How to tell the difference

Of course, not every silent call is a scam. Some are simply accidental calls or “pocket dials”, but there are clues that can help people tell the difference.

“If the calls come repeatedly, or from several different numbers, that’s suspicious. Scammers tend to use long or seemingly unusual international numbers, and there’s often no sign of a real person at the other end of the line. No breathing, no background chatter,” Amiruddin highlighted.

In contrast, genuine accidental calls usually have some background sound, or will end quickly when the caller realises the mistake.

“Sometimes, the real giveaway is what happens next, such as a follow-up call from someone claiming to be from the bank, police or even the court,” he added.

What you should do

So, what should you do if you receive a silent call? Amirudin’s advice is simple: hang up immediately.

Ending the call right away prevents scammers or automated systems – known as robocalls – from marking your number as active.

Still, he understands why some people hesitate. “Many worry that if they don’t answer, they might miss a call from a loved one in distress.”

But if the call were truly important, he added, the caller would try repeatedly or leave an SMS, WhatsApp or voice message.

Whatever happens, do not keep the line open or reveal any personal details. “As a precaution, report any suspicious numbers to the authorities,” Amirudin advised.

He also advised the public to check with the Malaysian Communications and Multimedia Commission or their telco provider to verify a number and report persistent spam activity.

Staying a step ahead

Your smartphone may automatically detect and filter spam calls, but blocking suspicious numbers is only one layer of defence.

According to Amirudin, a proactive approach to safeguarding personal data is crucial. This includes:

• avoiding sharing personal phone numbers publicly;
• educating family members, especially older relatives, on scam tactics;
• using separate numbers for personal and public use, where possible;
• monitoring financial accounts regularly and verifying suspicious calls by contacting organisations through official channels.

“Scammers are always finding new ways to reach you,” Amirudin concluded. “Your best defence is awareness and caution before you answer.”