Last month we highlighted Firesheep, a new Firefox extension designed to sniff out weak security and hijack website credentials on open Wi-Fi networks. BlackSheep is an anti-Firesheep tool, designed to alert you whenever Firesheep is active on your local network.
Zscaler, a company specialising in security measures for cloud-based computing services, created Blacksheep to counteract Firesheep session hijacking. Once installed, Blacksheep broadcasts fake credentials to essentially fish for Firesheep installations on the network.
When one is detected it displays the alert seen in the screen capture above. The configuration of Blacksheep is dead simple; by default it goes fishing every five minutes, but you can adjust it down to one minute. Blacksheep is a free tool and works wherever Firefox does.