Ripple effect from CDK hack widens as more US auto dealers flag hit Yahoo FinanceCar dealerships in North America revert to pens and paper after cyberattacks on software provider ABC NewsGroup 1 Automotive taking measures to protect systems after CDK cyber hack CNBCWith Pen and Paper in Hand, Car Dealers Improvise as Cyber Outage Persists The Wall Street JournalGroup 1 Automotive says CDK cyberattack has disrupted some U.S. operations MarketWatch