The payroll services hacker can simply download or copy the information to some other system of his own and use the same to perform unauthorized transactions and fund transfers. Although banks deploy double-layered verification methods to mitigate such frauds, the process is far from being full-proof.
Thus, payroll services think twice before you trust third party hotel and ticket booking service. Even the best hotel booking service providers are vulnerable to such server attacks by cyber experts and they do very little to plug the loopholes in their systems and servers.