Uber Technologies on Friday said that it is responding to a cybersecurity incident involving a breach of its network. The ride-hailing company confirmed that it has reached out to law enforcement after a hacker allegedly breached its network that forced Uber to take several internal communications and engineering systems offline on Thursday. The hacker reportedly compromised the account of an employee’s workplace messaging app Slack and used it to send a message to Uber employees announcing that the company had suffered a data breach.

As per a report by The New York Times that cited an Uber spokesperson, a hacker compromised an employee’s workplace messaging app Slack and used it to send a message to Uber employees saying that the company had suffered a data breach. The hacker reportedly got access to other internal systems later and posted an explicit photo on an internal information page for employees. The report further adds that the hacker is 18 years old and hacked Uber’s systems because the company had weak security.

Uber via a tweet on Friday acknowledged the data breach saying that it has reached out to law enforcement for investigating the incident. The company assured that it will post additional updates on Twitter as they become available.

The San Francisco-based company’s Slack communication system was taken offline on Thursday afternoon after employees received the message from the hacker, the report adds citing two employees.

According to the report, the person who claimed responsibility for the hack said he gained access through social engineering. He reportedly sent a text message to an Uber worker claiming to be a corporate information technology worker and persuaded the employee to hand over a password that gave them access to Uber’s systems.

Back in November 2016, a data breach affected 57 million passengers and drivers of the ride hailing service.