>> As border skirmishing increased last year, malware began to flow into the Indian electric grid, a new study shows, and a blackout hit Mumbai. It now looks like a warning. >> Four months later and more than 1,500 miles away in Mumbai, India, trains shut down and the stock market closed as the power went out in a city of 20 million people. Hospitals had to switch to emergency generators to keep ventilators running amid a coronavirus outbreak that was among India’s worst. >> Now, a new study lends weight to the idea that those two events may well have been connected — as part of a broad Chinese cybercampaign against India’s power grid, timed to send a message that if India pressed its claims too hard, the lights could go out across the country. >> The study shows that as the standoff continued in the Himalayas, taking at least two dozen lives, Chinese malware was flowing into the control systems that manage electric supply across India, along with a high-voltage transmission substation and a coal-fired power plant. >> The flow of malware was pieced together by Recorded Future, a Somerville, Mass., company that studies the use of the internet by state actors. It found that most of the malware was never activated. And because Recorded Future could not get inside India’s power systems, it could not examine the details of the code itself, which was placed in strategic power-distribution systems across the country. While it has notified Indian authorities, so far they are not reporting what they have found.