Ukraine's military intelligence agency (HUR) has carried out a cyberattack on several facilities in Russian-occupied Crimea on June 27, a source in the agency confirmed to the Kyiv Independent.
HUR has reportedly carried out several cyberattacks in recent months.
The agency attacked Russia's largest Internet providers operating in the peninsula a day earlier.
The attacks targeted the servers of propaganda media, telecom operators, and the system for registering and controlling traffic on the illegally-built Kerch (Crimean) Bridge, according to the source.
The work of local accounting systems was reportedly obstructed, while cash registers in Kerch and Sevastopol retail outlets were also disabled. The mass phishing attacks on local Internet users are continuing, the source added.
The mass DDoS attack affected the website of the Russian propaganda media Kerch FM and the servers of the mobile operator Miranda Media, which provides communication channels for the Sevastopol authority's call center.
The traffic registration and control system were also attacked, resulting in a long queue of cars trying to cross the Kerch bridge.
"Within an hour, the traffic jam increased sixfold, and in the morning, there were about 300 cars in the queue," the source said.