(Yicai Global) Feb. 15 -- Shares of Chinese couriers, including ZTO Express, S.F. Holding and Yunda Holding, sank after 4.5 billion pieces of customers’ private data, including information related to express delivery orders, were allegedly leaked online recently.

S.F. Holding [SHE: 002352] closed down 2.2 percent at CNY55.90 (USD8.20) today, while YTO Express Group [SHA: 600233] slumped 5.8 percent to finish at CNY18.83. Yunda Holding ended 2.9 percent lower at CNY13.64.

The rumor had nothing to do with YTO Express, a staff member at the Shanghai-based courier's security department said, adding that the firm was running normally.

On Feb. 12, the main channels of instant-messaging platform Telegram mass-forwarded a link to a privacy info search bot. DB App Security said in a WeChat article today that online sources said the bot had a 435-gigabyte database, including 4.5 billion pieces of personal information seemingly from China’s e-commerce and express delivery platforms.

Users only needed to enter a mobile phone number, and the bot would provide the owner’s real name, delivery address details and other private information, it added.

The 21st Century Business Herald cited a data security expert as saying that the data breach was more extensive, involving express delivery order information from many platforms. Due to the huge scale of information leaked, it is not possible to determine the specific cause at the moment.

Asked to verify the leak’s authenticity, S.F. Holding and online retail giant JD.Com said they had not received any relevant information. Alibaba Group Holding’s online shopping platform Taobao did not respond for comment.

Chinese laws prohibit the sale or provision of private information to others. A person is deemed to have committed a crime if they sell or provide 5,000 pieces of such data. Illicit gains from such acts will be confiscated, and a fine amounting to more than 100 percent but less than 1,000 percent of the gains will be imposed. In the case of no unlawful gains, a fine of less than CNY1 million (USD146,197) can be imposed.

Editor: Peter Thomas