An attack was detected, originating from your system. Please contact the system administrator. Message

I just upgraded my Comcast internet and now my website is giving me a "An attack was detected, originating from your system. Please contact the system administrator." message.
I use an internal DNS server and all other websites are ok.  Where should I start ?
Tim DawsonIT ManagerAsked:
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Rich WeisslerProfessional Troublemaker^h^h^h^h^hshooterCommented:
Please clarify what you mean by "my website"... what site do you mean exactly?

I suspect that there is a small chance that, if you are running a server, that your server has been compromised.
I think more likely, that you have malware on your system and an intrusion detection system provided by your upgraded Comcast internet is attempting to protect you (but mostly the rest of their customers and the internet) by blocking your access.
From a system or network which isn't experiencing problems, you can download Malwarebytes for personal use.  I'd install that, and let it scan.  It isn't definitive if it comes back negative, but it's where I'd start.  

Then I'd contact Comcast support to find out if your system/IP has been black-listed, and/or if they have more information about the message.

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