(Bloomberg) -- The hack of a technology vendor for real estate financiers left major American banks and mortgage lenders working Sunday to assess whether they were affected by the data breach. The vendor, SitusAMC Group Holdings, LP, said in a statement Saturday that someone compromised its systems and took client data including “accounting records and legal agreements.” The company said it learned of the intrusion on Nov. 12 and that it’s still assessing the scope and impact of the breach with outside expe ...