A mystery group stole 400GB of data detailing which governments are using Italian software to spy on people

An unknown group managed to steal and publish online over 400GB worth of data from the Italian "Hacking Team," the firm behind one of the most commonly used surveillance tools in the world.

The stolen data appeared on BitTorrent over the weekend and includes a wealth of information, including the source code of some of Hacking Team's products, email messages, audio recordings, and client details.

The unknown attackers added insult to injury by hijacking control of Hacking Team's Twitter account and using it to tweet screenshots of stolen emails.

Hacking Team is responsible for several tools used in government surveillance, including the DaVinci software. The software is commonly viewed as "legal malware" by security experts and is a key reason Hacking Team is listed as an "enemy of the Internet" by activist group Reporters Without Borders.

"Hacking Team's 'DaVinci' Remote Control System is able to break encryption and allow law enforcement agencies to monitor encrypted files and emails, Skype and other Voice over IP or chat communication," according to the Reporters Without Borders advisory on DaVinci.

"It allows identification of the target's location and relationships. It can also remotely activate microphones and cameras on a computer and works worldwide."

DaVinci's infamy rose in 2013 when security company Kaspersky published evidence hackers, believed to be state-sponsored, were using the software to spy on political activists from the Middle East.

At the time of publishing, the hackers were still leaking information online. The hackers have already leaked information regarding requests and payment information from customers in a variety of locations.

Key locations include the United States, Russia, Germany, Australia, Italy, Poland, Spain, Switzerland, South Korea, Singapore, Thailand, Ethiopia, Morocco, Nigeria, Sudan, Mexico, Panama, Chile, Colombia, Ecuador, Oman, Bahrain, Saudi Arabia and Egypt.

Privacy activist Christopher Soghoian has reported finding a more comprehensive leaked file containing a spreadsheet detailing all Hacker Team's existing government customers.

Business Insider was working to confirm this claim at the time of publishing and will update this article as new information appears.