Researchers at Cisco have been tracking the malware for months and suspect Russia is responsible -- the company alerted US and Ukraine authorities to its findings, though is not aware what the hackers are planning. US Homeland Security agents are investigating the malware, which has similar code to malware the government claims Russia used in prior attacks.

Security researchers have kept an eye on potential risks in Ukraine after recent attacks. Russian hackers were believed to be behind a Ukraine power grid outage in 2016. Last June, the NotPetya attack hampered banks, an airport and businesses in Ukraine and Russia before spreading elsewhere -- the US and the UK both claimed Russia was behind the assault, which the Kremlin denied.