Several commercial spyware vendors developed and used zero-day exploits against iOS and Android users last year. However, their exploit chains also relied on known vulnerabilities to work, highlighting the importance of both users and device manufacturers to speed up the adoption of security patches.

“The zero-day exploits were used alongside n-day exploits and took advantage of the large time gap between the fix release and when it was fully deployed on end-user devices,” researchers with Google’s Threat Analysis Group (TAG) said in a report detailing the attack campaigns. “Our findings underscore the extent to which commercial surveillance vendors have proliferated capabilities historically only used by governments with the technical expertise to develop and operationalize exploits.”