38,000 files of sensitive information about security systems in banks and the Swedish Parliament, among others, have been leaked to the Internet, says Dagens Nyheter.
Gunnebo reported on the cyber attack in August, but claimed at the time that the attempt was quickly blocked.
However, according to DN, hackers managed to export a huge amount of secret data and 19GB of material would have already been published on the open network.
Gunnebo specializes in security-related products such as access control, cash handling and safes.
Among the customers are banks, companies and even the parliamentary administration has used Gunnebot to procure the security systems for the parliament building.
The leaked information shows, among other things, the exact locations and drawings of customers' surveillance cameras, alarm devices, vaults and security rooms.
The expert interviewed by DN considers the leakage of building security systems to be problematic.
If it were just security codes, they could be changed quickly, but changing physical systems takes time.
Gunnebo CEO Stefan Syrén tells DN that the company does not intend to pay for or be associated with the money demanded by the blackmailers.
Gunnebo investigates how big a hack it is
- It is unfortunate that information has been stolen from us.
We go through the material and if there have been sensitive data leaks we are in touch with our customers.