Providing a user with assurance that a computer is secure based on a vulnerability assessment completed by a browser-compatible scanner operating on the computer. If the scanner finds a vulnerability, the scanner can inform the user that the machine is or may be compromised, or repair the vulnerability. For example, the scanner may be able to repair the vulnerability of the workstation. In the alternative, the scanner can provide the scan results to a network server. If the vulnerability assessment shows that the workstation is compromised, or if the possibility of remote compromise is high, the network server can decline to provide network services to the workstation.