A significant data breach at Knownsec, a Chinese cybersecurity firm, leaked over 12,000 classified documents detailing advanced state-sponsored cyber tools and a list of global surveillance targets. The breach, which occurred in November 2025, revealed extensive cyber espionage activities and sophisticated attack methods.

Over 4 billion user records, including sensitive financial, WeChat, and Alipay data, were exposed in what is believed to be the largest data leak in China’s history. The dataset, comprising 631 gigabytes, was left unprotected and is thought to have been collected for surveillance and profiling purposes. Affected individuals face significant risks with no clear recourse due to the anonymity of the data's source.