Well it is the Network Shield blocking it as it is on its list of malicious sites, see image.
Sucuri.net sitecheck doesn't find anything, image2, nor does URLVoid,
http://www.urlvoid.com/scan/blog.plughost.com.br/.
I don't know where your blog is hosted as we have seen instances like this where a hosting service that has multiple domains in its IP could be blocked, this would reflect on other domains using that IP.
- There is an on-line contact form,
http://www.avast.com/contact-form.php?loadStyles for: * Sales inquiries; Technical issues; Website issues; Report false virus alert in file;
Report false virus alert on website; Undetected Malware; Press (Media), issues.
- If you are reporting an FP, then you get another input field open, enter the web URL for the site you wish to submit for review (Network Shield), etc. A link to this topic also wouldn't hurt.
