Ukraine’s largest telecom operator Kyivstar has become the victim of a cyber attack, disrupting customers’ access to mobile and internet services.
“The cyberattack on Ukraine’s #Kyivstar telecoms operator has impacted all regions of the country with high impact to the capital, metrics show, with knock-on impacts reported to air raid alert network and banking sector as work continues to restore connectivity,” NetBlocks said in a series of posts on X.
Kyivstar, which is owned by Dutch-domiciled multinational telecommunications services company VEON, serves approximately 25 million mobile subscribers and more than 1 million home Internet subscribers.
The company said the attack was a “consequence” of the war with Russia and that it had informed law enforcement and special state services. While Kyivstar works to restore services, the internet watchdog noted that the telco is largely offline.
That said, Kyivstar has not yet provided details about the nature of the attacks and the reason for the shutdown. There is no evidence that customers’ personal data has been compromised in this incident.
“After stabilizing the network, all customers and corporate clients who could not use the company’s services as a result of the hacking attack will definitely receive compensation,” Kyivstar said in an update posted on Facebook.
It is also urging users to be wary of scams that aim to trick users into sharing their personal details and that “news about compensation and network restoration times will come exclusively from the company’s official pages.”
Pro-Russian hacktivist group Killnet claimed responsibility for the attack on Telegram, but did not provide any additional evidence to support its claims.
Killnet itself has been facing chaos for a few weeks after Russia-based Gazeta.ru exposed the real-world identity of its leader – known by the online alias Killmilk – as 30-year-old Russian citizen Nikolai Serafimov.
KillMilk has since announced that he was retiring, and appointed a new leader “Deanon Club,” who has claimed that “there will be a large-scale recruitment for the KillNet team, on all fronts” with the goal of striking government financial facilities, encryption firms, and the gambling sector.
The development comes after Ukraine’s Defense Intelligence (GUR) revealed that it has hacked Russia’s Federal Taxation Service (FNS) server. Office.ed-it.ru, a Russian IT company that served as a database for the FNS, was reportedly affected by the attack.
“During the special operation, military intelligence officers managed to infiltrate one of the well-protected key central servers of the Federal Tax Service (FTS of the Russian Federation), and then more than 2300 of its regional servers throughout Russia, as well as on the territory of the temporarily occupied Crimea,” the agency said.
However, Russian politician and legislator Anton Gorelkin said in a message on Telegram that the attack on FNS is imaginary, that it is an attempt by the Ukrainian government to “respond to their problems with Kyivstar”.