While analysing my websites statistics, I found that a bot with blank user agent tried to access the password protected pages of my sites. IP search ends up with the ISP provider "ALEXA INTERNET". Assuming that the bot belongs to Alexa, I am wondering why the user agent field is set to blank. The interesting thing is that whatever URL I'm entering into my browser address bar is tried to access by this bot from Alexa. I'm using FireFox with SearchStatus extension. Does this extension cause this problem in anyway?