Got a notice from Comcast that my iMac may be infected with a bot...does this appear to be SPAM to use their services? or is there something I can do to confirm infection on my own? See notification below: "Your immediate attention is required. Constant Guard from XFINITY identified that one or more of your computers may be infected with a bot. A bot is a malicious form of software that is used to send spam, host a phishing site, or steal your identity by monitoring your keystrokes without your knowledge. It may be possible you are unaware that your computer is infected with a bot. We strongly recommend you visit XFINITY.com/BotAssistance for important information on how to remove malicious software from your computer(s). "