There are good websites where you can find free information about brazilian stocks (or "ações" in portuguese) and these are some of them:
- fundamentus.com.br
- statusinvest.com.br
- fundamentei.com
- investsite.com.br
Some of them, like fundamentus and statusinvest offer fundamental data filters.
The fundamentei has an quality evaluation make by the community for each company. This evaluation is a number between 0 and 5, being 0 the worst and 5 the best.
The investsite has detailed information about the company balance sheet.