Security Shield is a renewed version of malware called Security Tool which has been actively infecting computers and has infiltrated a lot of them. GUI of Security Shield appears to be just like Security Tool’s, so this program can be predicted to use the same misleading tactics as the previous malware did. Beware, this scam installs onto one’s PC through other malware and fake online scanners. You should uninstall it as soon as possible. Don't buy upgrades for it, cause you will be scammed. Ignore all warnings that this fake program shows. It even blocks other legitimate programs. Also, Security Shield makes some useful modifications that will allow it to launch just after computer’s reboot.