Week 15: Calls from fake authorities at record high – but it’s not all bad

16.04.2024 - The National Cyber Security Centre (NCSC) has been monitoring the phenomenon of fake calls from alleged police authorities for nine months now. In the last three weeks, reports reaching the NCSC about this phenomenon have almost tripled and account for the highest number of reports received since the contact point was founded. However, the high number of incoming reports is not all bad.

Since last summer the NCSC has been receiving an increasing number of fake calls purporting to be from the police. The scam starts with a phone call supposedly from the police or customs authority claiming, for example, that personal bank details have arisen in connection with a criminal offence. They try on different stories but what they all have in common is that a computer-generated voice speaking in impeccable English asks the person being called to press 1 to be put through to a ‘police officer’ to obtain further information.

After an initial wave of calls last autumn tailing off over the winter months, the number of reports has exploded in recent weeks. The attackers have obviously intensified their business model.

Reports per week in the category ‘Calls from fake authorities’
Reports per week in the category ‘Calls from fake authorities’

The trick with getting you to press "1"

The attacks are similar to the calls made in the name of Microsoft that have been observed for some time. Here, the fraudster calls the victim directly and claims that the caller's computer is infected. As most callers were quick to spot the scam, they either hung up immediately or vented their anger on the scammers. The perpetrators therefore came up with a more effective variant.

With the current variant, it is no longer a person who calls, but a software. The machine randomly tries Swiss phone numbers throughout the day. If the number is invalid, it simply moves on to the next one; if it comes across a valid number, the announcement is played and the victim is asked to press 1. Only after pressing 1 is the caller connected to the fraudster. And that is why they try to get you to press 1: Only those who believe the story, at least to some extent, are connected to the fraudsters in this way.

The high number of incoming reports is not all bad 

By using such a software, the number of calls that can be made is virtually unlimited. It could go through practically all the phone numbers in Switzerland in a day. The more aware the public are and immediately cancels the calls, the more calls the fraudsters' machine has to make in order to generate enough potential victims who are then connected to the fraudsters. However, the high number of reports made to the NCSC is also positive in that a large proportion of the public are alert, quickly spotting the scam and hanging up straight away.

Don’t call back, the number shown is faked

A Swiss mobile phone number almost always appears on the display for these calls. Often those submitting reports state that they missed the call and tried to call back. However, the true owner of the phone number has no idea that their number is being misused is certainly not from the police. In these cases, the number displayed has been faked. The callers use Internet telephony and can falsify or mask the phone number. Sometimes the number displayed is assigned, in other cases the number is not assigned to anyone.

As the number displayed may belong to someone who has nothing to do with the scam, it cannot simply be blocked. If the number were to be blocked, the connection of someone uninvolved in the scam would be blocked, which would have even more serious consequences for them in addition to the annoyance caused by numerous returned calls from irate members of the public. Having their mobile phone number misused is also very annoying for the owner. However, the calls do usually stop after a while. If this is not the case, the only option is often to change the phone number.


  • End such calls immediately. Neither the police nor other authorities make calls to gain access to your devices.
  • Do not allow anyone to remotely access your computer. If you gave remote access, it is possible that your computer has been infected.
  • The first step is to uninstall the remote access program.
  • If you suspect an infection, have your device checked immediately by a specialist and cleaned if necessary. The safest option is to completely reinstall the computer. However, do not forget to back up all personal data beforehand.
  • If you have suffered a financial loss, report the case to your bank and file a complaint.

Last modification 16.04.2024

Top of page