So common sense tells us not to trust signed software. This thread is not about auto allowing signed software, neither is it about auto blocking unsigned software to run. This thread is about blocking unsigned software to elevate. WHAT ARE THE BENEFITS OF BLOCKING UNSIGNED TO SOFTWARE TO ELEVATE? It makes it a lot harder for malware to survice reboot and makes it easier for your (other) security programs to block, disable and remove it from your PC. WHAT IS THE DOWNSIDE OF BLOCKING UNSIGNED PROGRAMS TO ELEVATE? In laymen's terms elevation means increasing the rights from the default medium integrity level (compared with Basic User rights) to high integrity level (comparable with Administrator rights). The default of UAC is still to allow unsigned software to elevate to high/admin rights. This was the setting which was used when Vista was introduced. With the introduction of Vista, the defaults for driver installation was set to block unsigned drivers (enforce driver signing). It was still possible to install unsigned drivers, but with Windows 10 Microsoft is also driver and third party components updates through its regular Windows Update mechanism. This software will be signed by Microsoft (Microsoft Windows Hardware Compatibility Publisher and Microsoft Windows Third Party Application Component), reducing the need to grant unsigned software administrator access to your sytem. Nine years after the introduction of Vista most software is signed, only some freeware and smaller software companies still release their software unsigned because of the cost related to software signing. WHAT ABOUT UNSIGNED MALWARE? From 2010 to 2014 the number of signed malware increased rapidly, see for instance this post. In the quarterly report of Mcfee (August 2015 report) a decrease of signed malware is reported. In Q3 about 1.8 million new samples of signed malware are discovered. When we put that in perspective of the total number of new malware samples found, signed malware only is 10% of the total.