Ukrainian civilians endured a second day of widespread mobile phone and internet outages after a major cyberattack struck on Tuesday.
The assault, attributed to Kremlin-backed hacking groups, targeted Kyivstar, the country’s largest mobile and internet provider, disrupting services for 24.3 million mobile subscribers and more than 1.1 million home internet users.
Two groups, Killnet and Solntsepek—both linked to the Russian state—claimed responsibility for the attack.
Killnet posted on Telegram that Ukrainian mobile operators and some banks were targeted, while Solntsepek asserted it had destroyed 10,000 computers, over 4,000 servers, and all cloud storage and backups belonging to Kyivstar.
The effects were acute in several regions. In Lviv, streetlights controlled by internet-connected automated power switches had to be disconnected manually at dawn. Nationwide, businesses were hampered: credit card payments failed in many places and numerous ATMs stopped working.
Essential national systems were also affected. Air-raid alert systems used to warn of incoming missile attacks experienced outages, forcing authorities to rely on backup alarms and alternative communication methods.
Kyivstar’s CEO, Oleksandr Komarov, described the incident as unprecedented—a major compromise of a civilian telecommunications provider that exacerbates the challenges Ukraine faces during its conflict with Russia.
“Restoring all additional services, in my view, will probably take several weeks,” Komarov said in televised remarks.
Initial reports suggest the intrusion occurred through an internal employee account, according to the New Voice of Ukraine.
Solntsepek has ties to the Sandworm group, which is associated with Russia’s military intelligence (GRU) and has been linked to past destructive campaigns such as the NotPetya worm, an attack that caused roughly $10 billion in global damage.
This attack highlights the growing cyber threat confronting Ukraine and the urgent need for robust, coordinated responses to protect critical digital infrastructure.
(Photo by Max Kukurudziak on Unsplash)
Related read: UK accuses Russia of sustained hacking campaign
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