Facebook revealed on Tuesday that it has added free downloads of anti-malware software to its abuse detection and prevention systems for users with infected devices. The service is provided with the help of security software makers F-Secure and Trend Micro. Facebook will recommend one of them based on the type of malware it detects. Here’s how it works: Infected users will see a popup notification with one of the suggested products when they sign onto Facebook. If you click Download, the app will install itself and run. You’ll receive the results of the scan as a notification in Facebook. When it’s finished, the software will uninstall itself. Since you don’t get to keep the software, this isn’t a substitute for keeping your own computer clean and secure, but it does provide a nice backup option on the chance that you do get attacked.