Cyber attacks caused major printing and shipping disruptions on Saturday in the Los Angeles Times and other major US newspapers, including those owned by Tribune Publishing Co. such as Chicago Tribune and Baltimore Sun.
The cyber attack appeared to have originated outside the United States, the Los Angeles Times reported, citing sources familiar with the situation.
The attack caused delays in distribution in The Times, Tribune, Sun, and other Saturday edition newspapers that shared production platforms in Los Angeles, the Los Angeles Times reported.
Tribune Publishing, whose newspaper also includes the New York Daily News and Orlando Sentinel, said it first detected the malware on Friday.
The West Coast edition of the Wall Street Journal and the New York Times was hit because it was printed on a joint production platform, the Los Angeles Times said.
U.S. Authority investigation
A spokesman for Tribune Publishing Marisa Kollias said the virus damaged the back office system used to publish and produce "newspapers throughout our property."
"There is no evidence that customer credit card information or personal information can be compromised," Kollias said in a statement.
The Wall Street Journal and the New York Times did not immediately respond to requests for comment.
Most San Diego Union-Tribune customers do not have newspapers on Saturday when the virus infects the company's business system and hinders its ability to publish, writes editor and publisher of the Jeff Light newspaper on its website.
A spokesman for the US Homeland Security said they were studying the situation.
"We are aware of reports of potential cyber incidents affecting several news outlets, and working with the government and our industry partners to better understand the situation," DHS spokesman Katie Waldman said in a statement.