815,000 followers on Twitter potentially affected.
Yahoo News' Twitter account was hacked yesterday in which an Ebola virus outbreak in Atlanta was hoaxed.
The tweet said: "BREAKING: EBOLA OUTBREAK IN ATLANTA! Estimated 145 people infected so far since Doctors carrying the disease were flown in from Africa."
The company immediately followed up with another tweet which said: "Earlier, an unauthorised tweet with misinformation about Ebola was sent from this account. Please disregard that tweet."
Yahoo did not clearly state whether its Twitter was hacked, or wheter it was posted by mistake, but said that it is looking into the matter.