PASSTEAL, as its name suggests, is a piece of malware that uses various password recovery tools to steal passwords stored in the browsers of its victims. The TrendMicro report names WebBrowserPassView and PasswordFox s PasswordFox as two of the tools that they have found bundled with PAS STEAL. Password stealing malware is particularly dangerous for users who share passwords across various online accounts, which is one of the many reasons that password sharing is a bad idea.
Source: https://threatpost.com/passteal-malware-lurking-file-sharing-sites-112112/77239/