Chinese hackers have attempted to access over 20 million accounts on Alibaba, China’s equivalent of Amazon, according to Reuters.
The intrusion was discovered in November, and the attackers have since been apprehended, according to the Ministry of Public Security.
Using a database of 99 million usernames and passwords from different websites they obtained, the hackers used Alibaba's cloud computing platform to input the details into Taobao. Of those 99 million user names, around 20 million were for Taobao accounts, according to the ministry.
The ministry insists that Alibaba’s systems uncovered and blocked most of the login attempts.
Although Alibaba has declined to describe how the hackers were able to manipulate Alibaba’s cloud computing system to carry out the attack, it says that a security flaw in the platform was not to blame.
"Alibaba's system was never breached," a spokesman said.
China is struggling to keep up with a rising number of domestic cyberattacks. Officials — including President Xi Jinping — have repeatedly insisted that Beijing is the victim of hacking, rather than the aggressor.
Alibaba's U.S.-listed shares dropped by as much as 3.7 percent in late Wednesday trade thanks to reports of the hack, analysts told Reuters.