Four years ago, NASDAQ servers were compromised by Russian hackers, who were somehow able to insert a “digital bomb” into the systems of NASDAQ stock exchange. The intruder was not a student or a teen, but the intelligence agency of another country, Bloomberg Businessweek reported. The malware that was actually used by the hackers exploited two mystery zero-day vulnerabilities exploited two unknown zero day vulnerabilities. It is unclear whether the hackers targeted software, and whether hackers used these vulnerabilities to infect NASDAQ systems or to exfiltrate data.
Source: https://thehackernews.com/2014/07/how-russian-hackers-placed-digital-bomb.html