The stories redirected to the Syrian Electronic Army, the newspaper said. The group that supports President Bashar al-Assad has previously hacked into the sites and Twitter accounts of other media outlets, including the BBC, the Associated Press and the Financial Times.
The Post said it was working to resolve the issue.
The hacker group said on its Twitter account that it had hacked into a service used by the Post and other news sites to recommend content. It claimed that Time magazine and CNN were also affected, but those news outlets did not mention a possible attack.