Russian hacker group Solntsepiok (In the Sun) claimed responsibility this Wednesday for a cyberattack that left an undetermined number of customers of the Ukrainian mobile phone company Kyivstar, which has some 24 million users, without service on Tuesday.
“We, the hackers” [piratas informáticos] “Solntsepica takes full responsibility for the cyber attack on Kyivstar, the largest operator in Ukraine,” the group said on the group’s channel on the Telegram social network.
According to the group, as a result of the attack, “10 thousand computers, more than 4 thousand servers and all cloud storage and backup systems” stopped working.
“We attacked Kyivstar because the company provides communications to the Ukrainian army, as well as Ukrainian government and security structures. All other structures that help the Ukrainian army, get ready,” the hackers warned.
The network outage occurred on Tuesday morning, leaving some users in Ukraine without service after dark.
Kyivstar CEO Alexander Komarov linked the cyber attack, described as the largest in the last two years, to the war the country is facing.
“The war with Russia has many dimensions, and one of them is cyberspace,” he said, attributing the failure to a “powerful cyber attack.”
Ukrainian army spokesman Vladimir Fito told Ukrainian television that the armed forces “use a slightly different communication system at the front” so “the situation will not affect the actions” of the armed forces.
Other private companies such as PrivatBank also reported system failures, and Vodafone Ukraine also had problems with apps and payment systems.
In Sumy (northeast), air raid sirens stopped working, the city’s military department reported on Telegram.
In Lviv, the local city council, a large western city, reported that a power outage affected the operation of the street lighting system.
One of the largest Ukrainian banks, Monobank, announced that it had become the target of a “DDoS attack.” [negação de serviço] massive,” its co-founder Oleg Gorokhovsky said on Telegram.
The Security Service of Ukraine (SBU) began an investigation into the incident, later confirming that the attack was carried out by Russian hackers.