Security Plus is described as 'browser extension powered by VirusTotal's API, which provides free checking of URLs for viruses. It uses up to 64 different antivirus products/scan engines to check for viruses that the user's own antivirus solution may have missed' and is an app in the Security & Privacy category. There are three alternatives to Security Plus for a variety of platforms, including Android, Mac, Online / Web-based, Windows and Android Tablet. The best alternative is VirusTotal, which is free. Other great apps like Security Plus are VTchromizer (Free) and PopupDB (Free).
VirusTotal is a free service that analyzes suspicious files and URLs and facilitates the quick detection of viruses, worms, trojans, and all kinds of malware. You can upload files up to 150 MB in size.