A self-defined Saudi hacker claimed he had published details of 400,000 Israeli-owned credit cards online, but the card firms on Tuesday insisted that only 14,000 cards had been affected.
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.
Even after Washington pointed the finger at North Korea for the massive cyberattack on Sony Pictures, some experts say the evidence is far from clear cut.
Internet hackers invaded an official Brazilian website on Friday, the third straight day Brazilian government websites had been attacked, as a similar attack in Peru prompted police to seek US assistance from the FBI.
A court in Armenia on Tuesday gave a four-year jail sentence to the alleged Russian mastermind behind a computer virus crime group which infected some 30 million computers worldwide.
A suspected LulzSec hacker group ally arrested in Britain faces charges that he took part in cyber attacks on companies in the United States, court documents show.
Hong Kong police said Sunday they had arrested a 21-year-old man after he reportedly said on social networking site Facebook that he would hack several government websites.
An Islamist group on Tuesday said it will carry out new cyber attacks on US banking targets, according to SITE Intelligence Group, following similar attacks last week in response to an anti-Islam film.
A Philippine hacker has posted online what he claimed to be the president's personal mobile telephone numbers, with Benigno Aquino's spokesman denouncing the act as "cyber vandalism".
Colombia's President Juan Manuel Santos on Wednesday tweeted that his Facebook page had been hit by the hacker group Anonymous, which took a swipe at the country's independence celebrations.