The investigation centers on whether the oil and gas company misled investors and the public about the financial implications of climate change and its effects, according to the Times.
ExxonMobil confirmed it received a subpoena from the attorney general's office, and is "assessing [its] response."
"We unequivocally reject allegations that ExxonMobil suppressed climate change research contained in media reports that are inaccurate distortions of ExxonMobil's nearly 40-year history of climate research that was conducted publicly in conjunction with the Department of Energy, academics and the UN Intergovernmental Panel on Climate Change," spokesperson Alan Jeffers said in a statement.
The Los Angeles Times reported last month that Exxon scientists knew as early as 1977 that the use of fossil fuel contributes to global warming, but has since perpetuated climate change skepticism. The company has denied doing so.
According to Forbes, ExxonMobil is the seventh-largest publicly traded company in the world.
The Department of Justice has been under pressure to investigate the company over these claims, with Democratic presidential candidates Hillary Clinton, Bernie Sanders and Martin O'Malley all supporting calls for an investigation.
"'Exxon Knew' just joined the category of truly serious scandals," Bill McKibben, an environmental activist and founder of 350.org, said in a statement. "Just as New York's Teddy Roosevelt took on the Standard Oil Trust a century ago, New York's attorney general has shown great courage in holding to account arguably the richest and most powerful company on Earth. We hope that other state attorney generals and the federal Department of Justice, and the Securities Exchange Commission will show similar fortitude."
Schneiderman's office didn't immediately return a request for comment.