Ukraine’s largest mobile operator, Kyivstar, has confirmed it has suffered a powerful cyberattack on Tuesday morning that knocked out phone and internet service for millions subscribers. Kyivstar users were unable to make or receive calls and use internet services.
“This morning we were the target of a powerful hacker attack. It caused a technical failure, as a result of which services are temporarily unavailable: mobile communication; access to the Internet,” the company said in a post on Facebook.
The operator added that at present, there’s no indication that subscribers’ personal information was compromised in the incident. Currently, it’s unclear, what threat actor may be responsible for the attack. However, Kyivstar's chief executive implied Russia could be behind it.
The Security Service of Ukraine (SBU) has opened an investigation into the incident.
The outage has also impacted some POS-terminals and ATMs of PrivatBank, one of the largest banks in Ukraine, that use Kyivstar’s network. According to a PrivatBank’s spokesperson, the number of affected terminals and ATMs does not exceed 5%. Some other Ukrainian mobile operators like Vodafone have also been impacted due to influx of users.
But more importantly, air raid sirens in some regions of Ukraine stopped working as a result result of the outage.
Additionally, a Ukrainian online bank Monobank has also been hit with a cyberattack, according to its co-founder Oleg Gorokhovskyi.
Last June, Kyivstar’s president Oleksandr Komarov revealed that the Fancy Lazarus DDoS extortion group demanded a $250,000 ransom from the operator, threatening the company with massive high-volume distributed denial of service (DDoS) attacks, if the ransom is not paid. After the company refused to pay the ransom, Fancy Lazarus launched a massive 1.5 tbps DDoS attack against Kyivstar, which was thwarted.
