It is because of spy code in software extensions to the Chrome and Firefox browsers that surfing history of millions of users is registered and resold.

Part of the data surveyed comes from some of Sweden's largest companies - from which internal communications leaked, DN writes.

Staff matters with Swedes

The magazine, in collaboration with American security technician Sam Jadali, has taken advantage of a database that originally comes from one of the companies that sold surfing history.

The database shows, among other things, personnel matters about named Swedish employees, discussions between technicians about development plans and which documents and files have been downloaded.

Some of the companies involved are, according to DN, Ericsson, SAS, Husqvarna, Tele2, SKF and both AB Volvo and Chinese-owned Volvo Cars. Data from Assa Abloy, Verisure and Atea, an IT supplier to the Government Offices, among others, has also leaked.

Rocket engine failure leaked

According to security engineer Sam Jadali, there are also several international examples. Among other things, he could see information from space company SpaceX about the failure of a rocket engine for a vehicle transporting astronauts to and from the international space station ISS, DN writes.

The reason for the leaks is that many companies use internal work tools through the browsers. If an individual employee then has one of the software additions with a spy code, the surf traffic that is done with the work tool is also shared.

The newspaper has searched all the affected companies, and writes that several state that they look seriously at the issue and investigate the information, but that no one wants to comment on the specific event.