I have a website where it is being blocked for being on the Avast Blacklist. The blocking message displayed is the following "We aborted the connection to api.portalcredsystem.com.br safely, as it was infected with URL:Blacklist.
With this block my customers who use Avast are unable to pay their bills we need to solve this as soon as possible.
As you can see in the 3 links below, the url in question is clean.
First this is a bit strange in that the domain, portalcredsystem.com.br returns an error, yet add the api.portalcredsystem.com.br only then do I get the alert.
These may or may not have an impact on the detection.
You can use the - Reporting a Possible False Positive File or Website - https://www.avast.com/false-positive-file-form.php.
You should get a response in a day or two.
This site is under WAF protection so most of these web analytics tools won’t work anyway. The website it self does not respond on port 80 (http) but in the waf there is a redirect so that if the url is called using http the user will be redirected to https. Maybe if Avast uses these types of tests to define whether a site is malicious or not that starts to get worrying because in this case this analysis doesn’t make sense.