Cybercrime Southeast Europe Newsletter No. 120

Over 600,000 Fraudulent Calls: International Scam Network Linked to Serbia

When your phone rings and the number displayed on the screen appears to belong to a bank or the police, you probably would not immediately suspect fraud. This is precisely what criminal groups rely on when using modern technology to impersonate institutions that people trust.

A recent international police operation has revealed just how organised these scams can be and how important technical infrastructure can be in carrying them out.

According to a statement issued by the Government of the Republic of Serbia on 16 October 2026, two men were arrested in Smederevo on 7 October as part of an international operation known as “Silentium”. They are suspected of providing telecommunications infrastructure used to defraud people abroad.

According to information from German investigative authorities, more than 600,000 telephone calls were made through this infrastructure, which has been linked to over 18,000 cases of fraud.

In 70 cases, confirmed financial losses amounted to approximately €764,000, while the revenue generated from providing these services is estimated at around €1.6 million.

How does a scam work when a call appears to come from your bank?

One of the methods fraudsters use to gain victims’ trust is known as caller ID spoofing – a technique that allows a telephone number different from the actual originating number to appear on the recipient’s screen.

This means that someone may receive a call that appears to come from a bank, the police, or another institution, even though the person behind the call is a fraudster.

During the conversation, scammers may claim that the victim’s bank account has been compromised, that a suspicious transaction has been detected, or that urgent action is required to protect their money.

Their objective is to frighten the victim into disclosing confidential information, authorising a transaction, or transferring funds to an account controlled by the fraudsters.

Why is the case in Serbia particularly significant?

What makes this investigation especially interesting is that the suspects were not necessarily the individuals who directly communicated with the victims.

According to the authorities, their alleged role involved providing the technical resources that enabled large numbers of calls to be made while concealing their true origin.

This demonstrates that modern financial fraud is not necessarily the work of a single individual attempting to deceive people over the telephone.

Such schemes may involve organised networks in which different individuals perform different roles – from providing technology and communicating with victims to managing the accounts into which stolen funds are transferred.

For this reason, identifying and disrupting the technical infrastructure can be an important step towards uncovering a wider network of suspects.

How can you protect yourself from fraudulent calls?

The most important thing to remember is that the telephone number displayed on your screen is not reliable proof of the caller’s identity.

Even if a call appears to come from your bank, you should never disclose your PIN, passwords, one-time payment verification codes, or other confidential information.

Particular caution is necessary when the caller pressures you to act immediately, claims that you will lose your money unless you follow their instructions, or asks you to transfer funds to another account for their supposed protection.

In such situations, the safest approach is to end the call and contact your bank independently using its official telephone number.

What does Operation “Silentium” tell us?

This case demonstrates that financial fraud is becoming increasingly organised and that carrying out such schemes often involves cooperation between individuals operating in different countries.

At the same time, international police cooperation enables investigators to identify not only those who directly contact victims but also the infrastructure that makes these fraudulent activities possible.

The investigation serves as an important reminder that a seemingly ordinary telephone call may be connected to a much more complex criminal network.

Today, fraudsters do not necessarily need to know your password to try to steal your money. Sometimes, all they need is to convince you that you are speaking to someone you trust.

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