The BBC fell victim to a cyber attack on Christmas Day after a Russian hacker reportedly infiltrated a computer server and then tried to sell access to the broadcaster's system.
The BBC security team identified the attack and responded to the issue on Saturday, which is believed to have been resolved, according to a person familiar with the incident
The broadcaster refused to comment on the reports, insisting that it does not discuss matters of internal security.
The attack was first identified by Hold Security LLC, which monitors security breaches in search for stolen data.
The firm detected that infamous Russian hacker "HASH" was trying to sell access to the BBC server by showing files to other cyber criminals that could have only been obtained by breaking into the broadcaster's system.
The hacker reportedly infiltrated a file transfer protocol ( FTP) server, which is typically used to transfer large data files online.
The firm could not determine whether the hacker's conversations led to a deal or whether data had been stolen or damaged in the process.
"Accessing that server establishes a foothold within BBC's network which may allow an attacker to pivot and gain further access to internal BBC resources," Alex Holden, the company's founder and chief information security officer, told Reuters.
Given the size and global scale of the BBC's operations, the attack was "definitely a notch in someone's belt," he added.
This is not the first time the broadcaster falls victim to a cyber attack.
Earlier this year, the BBC was targeted by the Syrian Electronic Army, which supports President Bashar al-Assad, and has also taken aim at various news organisations including The New York Times and Associated Press.