Nasdaq OMX Group confirmed that its servers had been breached in February 2011. Hackers installed malware on sensitive systems, which enabled them to spy on dozens of company directors. Nasdaq didn’t immediately inform customers about the breach, after the FBI asked it to delay doing so so as to not impede its investigation. The most popular technique for compromising a Web-based application is to exploit well-known weaknesses in the Web application itself. Expect to see “virtual insider” trading having occurred.”]
Source: https://www.darkreading.com/attacks-breaches/nasdaq-server-breach-3-expected-findings