The Wiki Boat Brazil has claimed to have taken down the websites belong to Ministry of Finance(www.fazenda.gov.br) and Federal Police(dpf.gov.br ).
Few days back, they have also attacked the official website of Ministry of Foreign Affairs. According to hackers statement, they have attacked the site two times and site is down for 2 hours.
Besides, they have also discovered Cross site scripting vulnerability in few government sites. Central Bank of Brazil(bcb.gov.br) found to be vulnerable to Post XSS attack.
They've posted the proof-of-concept in pastebin:
Non-persistent XSS vulnerability has been discovered Brazil Federal Senate that failed to apply proper sanitizing method. It removes the script tags but h1 tag.