The Times, which was also affected by the attack, quoted a "source with knowledge of the situation" saying the attack was meant to disable infrastructure, rather than steal information.
"This issue has affected the timeliness and in some cases the completeness of our printed newspapers", Tribune Publishing spokeswoman Marisa Kollias said in a statement published by the Chicago Tribune.
"We believe the intention of the attack was to disable infrastructure, more specifically servers, as opposed to looking to steal information", the source said, adding the attacker was a "foreign entity".
Tribune Publishing said a computer virus disrupted production of the Chicago Tribune and its other newspapers.
"We apologize to our customers for this inconvenience", Light wrote. Technology teams made significant progress in fixing the problem, but were unable to clear all systems before press time.
The Sun Sentinel's Saturday edition was delivered Sunday because of the delays.
And staffers at some of the affected papers said they haven't received much information from management about the extent of the cyberattack.
A computer virus prevented most of the San Diego Union-Tribune's readership from waking up with a paper Saturday morning. "We are working diligently to resolve this matter".
In an internal memo, Tribune CEO Justin Dearborn said "workarounds" were created in order to print the affected papers' Saturday editions. At The Baltimore Sun, for example, the usual comics and puzzles were not included in Saturday's print edition, the paper tweeted.
Tribune Publishing news websites were not affected, and no customer information was compromised, the company said Saturday.
The company worked to come up with a workaround to produce the newspapers, but there were some delays in delivery.
The San Diego Union-Tribune is said to have been hit particularly hard, as 85 to 90 percent of its Saturday edition didn't reach its subscribers.