KIEV (Reuters) - An adviser to Ukraine’s interior minister said a version of the “WannaCry” ransomware had caused outages on government websites and those of several companies, a cyberattack he called the worst in Ukraine’s history.

Adviser Anton Gerashchenko said Ukrainian IT systems had been targeted with “Cryptolocker” a version of WannaCry, the virus that locked up more than 200,000 computers in more than 150 countries in May.

“The ultimate goal of the cyberattack was to try to destabilize,” he wrote in a post on Facebook in which he said the attacks probably originated from Russia.