Uber is investigating a cyber attack, after a hacker allegedly sent security experts evidence of the attack on its network.

A hacker sent several security experts images proving that he had access to the Uber network. They received images showing the structure of the cloud and part of the code used by the company.

One of the experts who corresponded with the hacker says that the evidence received shows not only that he was able to break into Uber’s network, but that he had full and unrestricted access, meaning that the company’s infrastructure was completely compromised, as presented by The New York Times.

Uber says it has shut down the internet of several systems to investigate the incident and see the extent of the attack.

Among the stopped systems is the one used for communication between employees using Slack. It seems that the attack was possible after the attacker gained access to the Slack account of one of the employees.

The hacker even sent a message on Slack to the company’s employees, saying that he had attacked the network and providing as evidence a list of several internal databases.

In communication with security experts, the hacker said he is 18 years old and attacked the Uber network because its security is weak. He also says he has access to source code, emails and various other systems.

The last notable attack on Uber took place in 2014, when hackers obtained the data of 50 000 drivers.