Almost a million Deutsche Telekom customers in Germany were taken offline following a suspected large-scale cyber attack.
The telecoms company says around 900,000 of its 20 million fixed-line customers were affected, with outages beginning on Sunday, November 27.
“Some customers are experiencing temporary problems or very marked fluctuations in quality, but there are also customers for whom the service is not working at all,” the firm said in a statement.
It then updated the page, writing: “According to our knowledge, an attack on maintenance interfaces is currently taking place worldwide.
“This was also confirmed by the Federal Office for Information Security. Following the latest findings, routers of Deutsche Telekom costumers were affected by an attack from outside.”
According to the latest update, the cyber attack was a failed attempt to infect routers with malware, but the company reassured customers that “there was no permanent infection with malware”.
Reuters previously cited government sources as claiming German security officials were discussing the possibility that cybercriminals were involved.
The report also states that Deutsche Telekom’s head of IT Security Thomas Thchersich told the newspaper Der Tagesspiegel that the attack seemed to be an attempt to turn customers’ routers into a part of the Mirai botnet.
Mirai is malware used to control network devices, turning them into “bots”, which are then used to carry out network attacks.
Last month, a botnet attack was mounted on DNS host Dyn in the US, which took dozens of websites, including Twitter and Spotify offline.
The large-scale DDOS attack was said to have been facilitated through a vulnerability in Internet of Things devices, which were used as ‘bots’ after being infected with Mirai malware.
Deutsche Telekom is advising affected customers to unplug their routers for a brief period, and plug them back in in order to reset the devices.