According to RIA Novosti, the hackers announced this in their Telegram.

“What happened today in Moldova?

Answer: there is a major failure on the https://servicii.fisc.md portal,” the message says.

As the hackers explained, today's hack will complicate the work of the department, as the days for the submission of tax and statistical reports for the previous month are coming.

Earlier, the founder of Killnet told RT what information was obtained after hacking the website of the American defense company Lockheed Martin, which produces HIMARS.