1

Bom dia, houve relatos de usuários que não conseguiram acessar o site da instituição:
www.porto.ifto.edu.br

2

This is a English forum and not for reports about (possible) false positives.

Use one of the non-English forums or post in English in https://forum.avast.com/index.php?board=4.0

3

Blacklisted
https://virustotal.com/en/url/f5bbb7609e3a9f1ec2e83fbf6d92b95a41106ccacb5e6064e6b323d8a968dfcb/analysis/1497895443/

porto.ifto.edu.br > INFECTED
https://www.virustotal.com/en/file/45626bfd37a1144511e5b1e4e51b22bd68a2a939c1745703adef367b2345f273/analysis/1497878409/

Sucuri sitescan >> https://sitecheck.sucuri.net/results/www.porto.ifto.edu.br

4

Thank you all!
Through the links they sent, I was able to identify the problem!