Enlarge / ATM at a Patelco Credit Union branch in Dublin, California, on July 23, 2018. (credit: Getty Images | Smith Collection/Gado ) A California-based credit union with over 450,000 members said it suffered a ransomware attack that is disrupting account services and could take weeks to recover from. "The next few days—and coming weeks—may present challenges for our members, as we continue to navigate around the limited functionality we are experiencing due to this incident," Patelco Credit Union CEO Erin Mendez told members in a July 1 message that said the security problem was caused by a ransomware attack.