BestXsoftware Best Free Keylogger before 6.0.0 allows local users to gain privileges via a Trojan horse "%PROGRAMFILES%\BFK 5.2.9\syscrb.exe" file because of insecure permissions for the BUILTIN\Users group.
https://github.com/ilsani/rd/tree/master/security-advisories/bestxsoftware/cve-2018-18519