Telekom launches "SMS firewall

Deutsche Telekom has announced that it will install a protective function for its own customers: An "SMS firewall". It is designed to protect recipients from malicious messages that could cause them to install malware or fall for scams.

Deutsche Telekom told heise online: "From April 1, 2025, we will be protecting customers in the Deutsche Telekom mobile network from malicious text messages with a so-called SMS firewall. As an integral part of the network, it will also work for Congstar and Fraenk customers." The company is initially "concentrating on text messages that contain a link to malware". Gradually, Telekom wants to "expand the focus as part of the introductory phase."

SMS as a gateway for malware and fraud

The old text message is still very much in use, Telekom told us: "The text message still performs well at the turn of the year: around five million text messages were sent by customers on the first night of the new year." Of course, harmful messages also arrive very often. Last year, there were thousands of complaints to the Federal Network Agency about being ripped off with alleged parcel text messages.

However, there was no concrete answer to our question, which we asked on the basis of inquiries from concerned readers, as to whether Telekom is now reading text messages. The dpa emphasizes in this regard that text messages, like telephone calls, are subject to telecommunications secrecy and are protected by the Telecommunications Act. Only in exceptional legal cases, such as for criminal prosecution, are mobile phone providers allowed to view or analyze the content of messages. This makes it more difficult to detect fraudulent text messages.

Telekom therefore checks "technical data such as sending and receiving information, date and time". The Telekom SMS firewall checks links contained in text messages for malicious content. According to dpa, Vodafone also fends off a large proportion of attacks from fraudulent or unwanted text messages such as spam. The company relies on a combination of systemic and manual network monitoring. As a result, 1&1 also uses firewalls and fraud management systems to control SMS traffic.

The limits of the Telekom SMS firewall lie with SMS where the text content represents the danger. This includes the more modern grandchild trick variants of the type "Hello mom/dad, this is my new number", which feign emergency situations in order to rip off money from the victims.

(dmk)