An unpatched vulnerability discovered in Chrome that is currently used by attackers to monitor users and collect some data from them. They send out PDF files, which are not malicious in nature. But if the victim opens it in the Chrome embedded PDF reader, data on the user's IP address, versions of the system and browser will flow to a third-party server.
Experts suggest that attackers collect information for future attacks.
Chrome developers promise to release a patch in late April. In the meantime, information security experts recommend either opening PDF files in desktop readers, or turning off the Internet while viewing them in a browser.