UK newspaper The Guardian said on Wednesday it had been hit by a "serious IT incident", a suspected ransomware attack, although its website was largely unaffected.
The incident, which hit parts of the newspaper group's technology infrastructure, began late Tuesday.
There has been some disruption to "behind-the-scenes services", while staff have been asked to work from home while the problem is resolved, the Guardian said.
"Online publishing is largely unaffected, with stories continuing to be written and published to the Guardian website and app," the newspaper added.
"We are confident we will be able to publish in print tomorrow," Guardian Media Group chief executive, Anna Bateson, and editor-in-chief, Katharine Viner, told staff.
"With a few key exceptions we would like everyone to work from home for the remainder of the week unless we notify you otherwise," they added.