MeDoc

MeDoc, also stylized as M.E.Doc, is a Ukrainian enterprise software product developed by M.E.Doc LLC for electronic document management, invoicing, and tax reporting. It is used by many Ukrainian businesses to prepare and submit electronic documents, including VAT declarations, invoices, and other reports to the State Tax Service.

The software provides modules for accounting, payroll, and electronic document exchange, and it has been widely adopted by public sector bodies and private companies to streamline administrative processes and e-invoicing compliance.

In June 2017, a major cyberattack known as NotPetya spread globally and was distributed through a compromised update mechanism in M.E.Doc. The attack infected thousands of computers in Ukraine and later affected organizations around the world, causing significant disruption and financial losses. Analysts described NotPetya as highly destructive and as a wiper, though it initially propagated via a Ukrainian accounting software update.

Following the incident, there was increased scrutiny of software supply chains and patch management in Ukraine and beyond. Some MeDoc users migrated to alternative solutions or implemented additional security controls, and the government introduced reforms to improve cyber resilience and e-invoicing security in Ukraine. MeDoc continues to operate as a product, but the event remains a notable reference point in discussions about Ukrainian digital infrastructure and cyber security.