Cyberattacks and Financial Stability: Evidence from a Natural Experiment

This paper studies the effects of a unique multi-day cyberattack on a technology service provider (TSP). Using several confidential daily datasets, we identify and quantify first- and second-round effects of the event. For banks using relevant services of the TSP, the attack impaired their ability to send payments over Fedwire, even though the Federal Reserve extended the time they had to submit payments. This impairment (first-round effect) caused other banks to receive fewer payments (second-round effect), leaving them at risk of having too few reserves to send their own payments (a potential third-round effect). These innocent-bystander banks responded differently depending on their size and reserve holdings. Those with sufficient reserves drew down their reserves. Of the others, smaller banks borrowed from the discount window, while larger banks borrowed in the federal funds market. These significant adjustments to operations and funding prevented the second-round effect from spilling over into third-round effect and broader financial instability. These findings highlight the important role for bank contingency planning, liquidity buffers, and the Federal Reserve in supporting the financial system’s recovery from a cyberattack.