Even old-school printed newspapers aren't immune from the pitfalls of technology.

Tribune Publishing said Saturday night that malware affected its ability to print newspapers across its chain of outlets, including the Chicago Tribune, the New York Daily News, the Baltimore Sun and the Orlando Sentinel.

Many subscribers to the Los Angeles Times and San Diego Union-Tribune, which were previously owned by Tribune Publishing and still share some production technology with the company, stepped into a chilly sunny morning Saturday only to find empty doorsteps.

The computer malware was detected Friday and "impacted some back-office systems which are primarily used to publish and produce newspapers across our properties," said Marisa Kollias, Tribune communications vice president, in a statement.

"There is no evidence that customer credit card information or personally identifiable information has been compromised," she said. "The personal data of our subscribers, online users, and advertising clients has not been compromised."

The Los Angeles Times, citing an anonymous source, described the malware as part of a cyberattack with foreign origins. The Times and the Union-Tribune were sold by Tribune Publishing to Los Angeles biotech billionaire Patrick Soon-Shiong in June.

Kollias said Tribune Publishing was putting a "workaround" in place.

"We have been actively working with all of the relevant vendors to resolve the systems issues and restore timely service to our customers," the Times said in its own statement. "However, it’s likely that the issues will affect the process of printing and delivering the Sunday newspapers as well."

Regional editions of the New York Times and Wall Street Journal, which are printed at the Los Angeles Times' Olympic printing plant downtown, also were impacted, the L.A. company said.

The Ventura County Star newspaper in Southern California also was affected, the paper said in a note to readers.

In the meantime, readers of the Los Angeles and San Diego newspapers were invited to view print-like digital editions online.