French security researcher Julien Voisin discovered the exploit. It targets Spectre, a major vulnerability that was disclosed in January 2018.
Voisin said he discovered new Spectre exploits -- one for Windows and one for Linux -- different from the ones before. In particular, Voisin said he found a Linux Spectre exploit capable of dumping the contents of /etc/shadow, a Linux file that stores details on OS user accounts.
For those who came in late Spectre along with the Meltdown bug, effectively forced CPU vendors to rethink their approach to designing processors, making it clear that they cannot focus on performance alone, to the detriment of data security. Software patches were released at the time, but the Meltdown and Spectre disclosures forced Intel to rethink its entire approach to CPU designs.
At the time, the teams behind the Meltdown and Spectre bugs published their work in the form of research papers and some trivial proof-of-concept code to prove their attacks. Shortly after the Meltdown and Spectre publications, experts at AV-TEST, Fortinet, and Minerva Labs spotted a spike in VirusTotal uploads for both CPU bugs.