Ukraine police prevent second cyber attack - minister

Ukrainian Interior Minister Arsen Avakov is seen before the meeting of national security and defense council of Ukraine in Kiev September 22, 2015. REUTERS/Gleb Garanich

KIEV (Reuters) - Ukrainian cyber police have blocked the second cyber attack against Ukraine, Ukrainian Interior Minister Arsen Avakov said on Wednesday.

Experts are still trying to establish who was behind an attack by a malware virus that crippled computer systems at major companies around the world.