Ukrainian Cyberattack Wipes Data From Government Servers in Russian-Occupied Crimea

Cyber specialists from Ukraine’s Main Intelligence Directorate (DIU) have carried out a large-scale cyber operation targeting the Russian-installed administration in occupied Crimea.

The sources in Ukrainian intelligence reported this to Militarnyi.

The operation, which lasted several days, began with a powerful distributed denial-of-service (DDoS) attack that disrupted key information systems and crippled network infrastructure across the peninsula.

While Russian authorities investigated the outage, Ukrainian cyber units reportedly gained access to government servers and internal systems. These included electronic document management platforms such as ‘DIALOG,’ ‘SED,’ ‘Delo,’ as well as accounting and workflow systems like ‘1C:Document Management,’ ‘Directum’ and ‘ATLAS.’

According to the source, roughly 100 terabytes of data from the so-called “Government of the Republic of Crimea” were exfiltrated. Among the files were documents marked ‘secret,’ including information on military installations and logistics routes used by Russian forces on the peninsula.

“We’ll soon see revelations about the activities and crimes of the Russian occupiers in Crimea,” the source said, adding that the operation had been made possible in part by access to the account of Anton Lyaskovsky, Deputy Minister of Health in the Russian-appointed Crimean administration.

After extracting the data, Ukrainian cyber specialists deleted all files from the targeted servers, affecting regional and district institutions, as well as ministries and departments under the occupation authorities.

Russian state media later reported on the breach, with lawmakers in Moscow describing it as an element of “hybrid warfare.” The Russian-installed Ministry of Internal Policy, Information and Communications in Crimea confirmed that recovery efforts were underway, but warned that some public services would remain unavailable.

Earlier this month, Ukrainian hackers also reportedly obtained internal documents from ‘Russian Helicopters,’ a major aircraft manufacturer, including records on its international partners and clients.