Hi, I am using Firefox browser and some time when logging in to some official sites it gives CAPTCHA to enter. Is this due to malware? How to overcome this? If it is due to some infection please suggest an AV and FW.
tns, CAPTCHA is not malware, and many Web sites do use it to make sure humans are entering information. There's no need to overcome it; just type what you see to gain access. More info: The Captcha Project.
tns, if you are seeing a Unusual traffic from your computer network is being detected notice, then read Google Captcha Removal Guide.