Used printer File Photo: Courtesy of Baomi Guan

Chinese national security authorities warned that some government departments and organizations' improper disposal of office equipment, including used printer toner cartridges, could pose serious risks to state secrets and sensitive data, unintentionally creating a "convenient gateway" for the theft and leakage of classified information.

Some government departments and organizations have insufficient awareness of the security risks associated with office automation equipment and lack basic knowledge of technical safeguards for protecting classified information, according to a notice released by the WeChat account "Baomi Guan," affiliated with China's National Administration of State Secret Protection.

The notice revealed a case in which an office supplier surnamed Zheng collected used printer toner cartridges from a government-affiliated organization under the guise of environmental recycling. Wang, an employee responsible for handling the equipment, handed over toner cartridges containing a large amount of classified state information. 

After simple operations, Zheng reproduced documents that had previously been printed by the discarded toner cartridges and sold them to an overseas organization. Zheng was later arrested in connection with an espionage case, which led to the exposure of the incident. Following the investigation, Wang was given Party disciplinary and administrative penalties by relevant authorities.

The notice stated that key components of classified information equipment, including toner cartridges, hard drives and memory modules, are "unnoticed repositories" of state secrets, and that residual information stored on these components can be recovered.

The notice explained that, according to the operating principles of laser printers, the photosensitive drum inside a toner cartridge records printed text and images through electrostatic patterns during the printing process. After recovering discarded toner cartridges, criminals may use certain tools and techniques to analyze residual electrostatic charges or toner distributions on the drum surface and partially reconstruct the outlines of previously printed documents under certain lighting and developing conditions.

Data stored in toner cartridge chips, including usage logs and device serial numbers, may also be vulnerable to malicious extraction. Therefore, if discarded classified information equipment enters public circulation without professional information erasure or physical destruction, it could lead to the leakage of state secrets and cause irreversible losses.

Authorities stressed that government departments and organizations must strictly distinguish between classified and non-classified information equipment and implement categorized management. The entire lifecycle of classified information equipment, including its use, repair, maintenance, and disposal, must comply with relevant confidentiality regulations.

The notice further stated that information stored on classified components must be erased, recovered, or disposed of only through officially designated organs. Strict procedures involving approval, inventory checks, registration, and handover must be followed. Unauthorized dismantling, transfer, donation, sale as scrap, or arbitrary disposal of classified equipment is strictly prohibited.

Global Times