Ukraine’s largest mobile carrier Kyivstar down following cyberattack

Kyivstar, Ukraine’s largest telecommunications service provider serving over 25 million mobile and home internet subscribers, has suffered a cyberattack impacting mobile and data services.

The official website is offline, but the company informed subscribers via its social media channels that it was targeted by hackers this morning, causing a technical failure that impacts mobile communications and internet access.

“This morning, we were the target of a powerful hacker attack. It caused a technical failure, as a result of which services were temporarily unavailable,” reads a statement from Kyivstar.

Kyivstar says they reported the incident to law enforcement and other state services. The SSU (Security Service of Ukraine) has opened criminal proceedings under 8 articles of the criminal code of Ukraine and stated that its special agents are involved in the investigations.

Independent internet observatory NetBlocks confirmed that Kyivstar internet services are currently unavailable, showing a sharp drop in traffic as of this morning.

Kyivstar’s statement also assures subscribers that this security incident has not compromised any personal data and that all impacted subscribers who cannot use Kyivstar’s services will receive compensation.

Considering the ongoing conflict between Ukraine and Russia, it is plausible that Russian hackers orchestrated the attack, as suggested by SSU’s announcement and Kyivstar’s CEO public address. Nonetheless, the exact source of the attack remains unconfirmed.

For those impacted by the outage, Vodafone Ukraine stated on X that their roaming service is available, noting that Lifecell subscribers are already taking advantage of their services.

Since the start of the war, Ukrainian telecommunication firms have established a resilient system of free internal roaming. 

When an operator becomes unavailable in a given area, which isn’t rare under current conditions, users can switch to another operator’s network to regain mobile services.

Ukrainian Interior Minister Igor Klimenko stated on local news outlets that Ukrainians can use emergency numbers 101, 102, and 112 under any condition. At the same time, it’s possible to contact relatives by visiting the nearest police or fire department.

Update 12/12 – NetBlocks reports that the Kyivstar outage impacts internet access across all regions of Ukraine, and it has hampered the air raid alert network people use to get timely notices about incoming bombing attacks.

Original Source