The victim plays a central role in Denmark's governmental infrastructure, holding sensitive information on the nation's shipping companies and merchant navy.
According to sources, in April 2012, a foreign state-sponsored cyber intrusion targeted the Danish Maritime Authority, other ministries, and companies of the private sector. The so-called "highly sophisticated attack" first used a phishing technique where a malicious virus was embedded in a PDF document attached to an email. When an unsuspecting employee of the Maritime Authority opened this compromised attachment, it granted the hackers back-door access to not only that particular computer but also an additional 13 PCs, several servers, and the larger Maritime Authority's network. The Danish authorities remained unaware of the security breach until files from the Maritime Authority were detected on a foreigh server, known to be under hacker control. This discovery led to the identification of the compromised files, which originated from the Maritime Authority employee's computer that had been infected through the virus email attachment.
There was a disclosure of sensitive business information. As a countermeasure, the Danish authorities shut down the compromised system and surrounding assets for several days. Only after implementing new anti-virus programs was the system reactivated. Several sources in Denmark underlined the attack as similar to Chinese-reputed Tactics, Techniques and Procedures (TTPs).