Researchers with Symantec have uncovered additional clues that point to Chinese hacker involvement in attacks against Western companies. The attacks use malicious PDF documents that exploit an Adobe Reader bug patched last month. One of the attackers who connected to the staging server did so from Zhejiang province on China’s eastern coast. Researchers also found clues that led it to a second system where the same group hosted a tool that automatically modifies files, again including PDFs, as part of its strategy to evade antivirus software.”]