Russia's Federal Taxation Service, or FNS, had its central and regional servers infiltrated in a cyberattack admitted to be conducted by Ukraine's Defense Intelligence service, BleepingComputer reports.
Aside from compromising all FNS servers with malware, such an attack has also wiped out configuration files supporting the taxation system of Russia, as well as impacted the third-party data center services provider of FNS.
While Russia has been working for four or more consecutive days to restore the services of FNS, significant outages are expected within the next month, according to Ukraine's Main Directorate of Intelligence, or GUR, which dismissed the possibility of total restoration.
"This means a complete destruction of the infrastructure of one of the main state bodies of terrorist Russia and numerous related tax data for a long period," said GUR.
Such claims come just weeks after the GUR took responsibility for hacking Russia's civil aviation authority Rosaviatsia and leaking its data.
Ukraine has been targeted by Russian threat actors in the new Operation Texontodisinformation campaign that also involved spear-phishing and credential exfiltration tactics, according to The Hacker News.
Record high ransomware and data extortion incidents experienced by Western nations last year have prompted former National Security Agency Director Michael Rogers to call for a reevaluation of their cybersecurity defense strategy.