PALO ALTO, Calif. — In late 2013, an A.T.M. in Kiev started dispensing cash at seemingly random times of day. No one had put in a card or touched a button. Cameras showed that the piles of money had been swept up by customers who appeared lucky to be there at the right moment.
But when a Russian cybersecurity firm, Kaspersky Lab, was called to Ukraine to investigate, it discovered that the errant machine was the least of the bank’s problems.