When using the "Advanced Method" API or when viewing details in the "Thumbnail History", you may see "NS_ERROR_MALWARE_URI.
For this test, we use the Mozilla toolkit repository. They maintain a database of listed websites that are reported as malicious or compromised. The request attempting to be captured has been reported to that database. It could be a false positive or the site could have been fixed since the report was made.
Typically, any false positives will be cleared on their own, over time. You may also be able to contact Mozilla about the issue and ask if there is a way to get the site removed from their "MALWARE" database. This has only been an issue once before, and we do not know "how" to ask for removal. If anyone works through this process, we would love to hear how you did it so that we can update this article.
Keywords: malware malicious compromised hacked sites