The personal data belonging to an astounding 35 million people in South Korea may have been compromised this week when hackers infiltrated SK Communications, which runs the Asian nation's largest social networking site, Cyworld, and third-most trafficked search engine, Nate, according to published reports. The Korea Herald reported that officials at SK Communications, part of the SK Group, blamed malware that could be traced back to China. Experts fear the compromised data, which includes usernames, phone numbers, email addresses and passwords, could be used in other attacks that seek even more sensitive information.