In January 2010, Google detected a "highly sophisticated" cyberattack on its infrastructure that originated from China. The targets of the attack were Chinese human rights activists, but Google discovered that accounts belonging to European, American and Chinese activists for human rights in China had been "routinely accessed by third parties". Additionally, Google stated that their investigation revealed that "at least" 20 other large companies from a "wide range of businesses" - including the Internet, finance, technology, media and chemical sectors – had been similarly targeted. Google was in the process of notifying those companies and it had also worked with relevant US authorities. In light of the attacks, Google enhanced the security and architecture of its infrastructure, and advised individual users to install anti-virus and anti-spyware on their computers, update their operating systems and web browsers, and be cautious when clicking on Internet links or when sharing personal information in instant messages and emails.