A “man-on-the-side” attack called Quantum Insert is a tool used by advanced persistent threat groups. The technique was reportedly used successfully by the NSA and Britain’s GCHQ intelligence service against OPEC and Belgian telecommunications company Belgacom. Fox-IT has published the code for detecting Quantum Insert and released it on GitHub. The Dutch security company has developed a tool to detect a Quantum Insert attack on a target website. It’s not a method that would be used to target a large number of people, like government-sponsored organizations.”]
Source: https://www.csoonline.com/article/2914236/fox-it-releases-answer-to-nsas-quantum-insert-attack.html