The computer hacker group Anonymous attacked websites of Brazil's federal district Saturday as well as one belonging to a Brazilian singer to protest the forced closure of Megaupload.com.
Hacker group Anonymous blocked the official website of Argentina's National Institute of Statistics and Census amid an international stand-off over claims the country has lied about its economy.
A group of computer hackers on Thursday claimed to have breached NATO security and accessed hoards of restricted material.
Russian-based hackers are using malicious software concealed in Twitter images to relay commands and steal data from US computer networks, security researchers said this week.
Hacker group Anonymous released a trove of military email addresses and passwords it claimed to have plundered from the network of US defense consulting firm Booz Allen Hamilton.
Notorious hacker group Anonymous on posted a defiant message to police Thursday and boasted of plundering sensitive data from NATO computers.
Greece's justice ministry on Wednesday sustained a cyber-attack, the second this month, after the arrest of a teenager accused of participating in the first hacking, police said.
Hackers have targeted the public websites of the operators of the Nasdaq and Bats stock exchanges over the past two days with cyberattacks that disrupted the sites but had no impact on trading.
A hacker group on Wednesday brazenly ramped up its antics as unrelenting waves of cyberattacks expose how poorly defended many networks are against Internet marauders.
Hackers who have hit the websites of the CIA, US Senate, Sony and others during a month-long rampage claimed on Monday to have knocked the site of Britain's Serious Organized Crime Agency (SOCA) offline.