A group of hackers suspected to have links to the Chinese government breached computer systems belonging to New York's Metropolitan Transit Authority (MTA) in April, according to the New York Times.
Transit officials told The Times that the breach did little damage and hackers did not gain access to train controls.
A forensic analysis of the attack further found that hackers did not access nor compromise customers' personal data or put riders in danger, The Times reported. The hack was reported to law enforcement and other state agencies but was not announced to the public.
"The M.T.A.'s existing multilayered security systems worked as designed, preventing spread of the attack," Rafail Portnoy, the MTA's chief technology officer, told The Times. "We continue to strengthen these comprehensive systems and remain vigilant as cyberattacks are a growing global threat."
It was not immediately clear why hackers thought to have ties to the Chinese government tried to access the MTA's computer systems, but investigators theorized that it could be linked the country's efforts to dominate the rail car market, according to The Times.
Another theory, given the lack of changes made in the breach, could be that "hackers mistakenly entered the M.T.A.'s system and discovered it was of little interest," The Times reported.
The April cyberattack on North America's largest transit network marked the third and most significant breach by hackers with suspected foreign government ties in recent years, transit officials told The Times.
The MTA hack is the latest in a string of cyberattacks that have struck US agencies and companies in recent months, including a cyberattack in the past week against major meat producer JBS.
The MTA breach follows another major ransomware attack last month on the Colonial Pipeline, one of the largest pipelines in the US. Hackers shut down the Colonial Pipeline's network, preventing shippers from planning upcoming fuel shipments of fuel and leading to gas shortages and price gouging throughout the US.
This is a developing story. Please check back for more updates.