Ukraine’s Kyivstar Hit by Worst Cyber Attack of War so Far 

Ukraine’s largest mobile network operator, Kyivstar, has been knocked offline by what appears to be the worst cyber attack of the Russia-Ukranian war so far. 

Millions of people across the country have been unable to access mobile or internet services as a result of the” powerful” cyber attack, with over 1.1 million home internet subscribers also knocked offline. 

Kvyvistar k has 24.3 million subscribers, providing mobile and internet access to over half of Ukraine’s population. 

The company is owned by the Amsterdam-listed mobile telecom operator Veon. In a statement, Veon said the network’s technical teams were “working on eliminating the consequences of the hacker attack and restoring communication as soon as possible.”

“They are working in close cooperation with Ukrainian law enforcement agencies to determine the circumstances and consequences of the interference in the Kyivstar network. 

“At the time of this release, the personal data of subscribers has not been compromised, to the best of Kyivstar’s knowledge.”

Kyivstar Cyber Attack: ‘an act of war’

Kyivstar’s CEO Oleksandr Komarov said the company's IT infrastructure had been "partially destroyed" as a result of the attack, calling the move an “act of war”.

“This is a war, it takes place not only on the battlefield, it also takes place in virtual space and unfortunately, we are affected as a result of this war,” Komarov said in a TV broadcast. 

"[The attack] significantly damaged [our] infrastructure, limited access, we could not counter it at the virtual level, so we shut down Kyivstar physically to limit the enemy's access," Komarov said.

Kyivstar users have been unable to make or receive calls and use internet services as a result of network takedown. Kyivstar’s network is also essential for payment systems in most shops.  

Representatives of PrivatBank and Oschadbank, two major Ukrainian financial institutions, also told media outlet Hromadske that part of their ATMs and card terminals had been affected by the Kyivstar outage.

In a separate incident, the co-founder of Monobank, a major Ukrainian payment system, said in a social media post that his company was currently suffering a DDoS attack, but that everything was "under control". He added that the attack had been fought off.

Russia’s Cyber Offensive 

It is not yet known which group is behind the cyber offensive. Komarov said the attack was a result of Ukraine’s war with Russia but did not say which specific group could be behind it. 

It’s not the first time Russia has targeted Ukraine’s critical national infrastructure.  In May 2022, the UK’s National Cyber Security Centre suggested that Russia was behind a cyber attack on a global communications company in Ukraine that affected windfarms and internet users in central Europe.

Russian state-sponsored groups have also targeted the infrastructure of Ukraine’s allies. Just last week, the UK accused the Russian spy agency Star Blizzard of targetting British politicians, journalists, and public organisations in several ‘sustained’ cyber attacks over several years. 

Pro-Russia gangs like LockBit and KillNet have also claimed responsibility for some of the biggest cyber attacks of recent years.

These include the MOVEit vulnerability hacks that targeted US government agencies earlier this year and the ransomware attack against the NHS in August 2022 that left doctors keeping patient records on scraps of paper.