Law enforcement officials and cyber experts are still working to compile a chronology of events, draw up a list of compromised accounts, and determine the penetration point, while tracing computers potentially infected with malware in sleep mode, it said. The comments make no mention of which individual, group or country may have been behind the attack. "It was an intentional cyber incident not meant to be on a large scale... they actually attacked more but couldn't achieve all their goals," said Marina Krotofil, lead cyber-security researcher at Honeywell, who assisted in the investigation. In December 2015, a first-of-its-kind cyber attack cut the lights to 225,000 people in western Ukraine, with hackers also sabotaging power distribution equipment, complicating attempts to restore power. Ukrainian security services blamed that attack on Russia.