Real-life pirates—the swashbuckling kind, not digital thieves—are hacking into the systems of shipping companies in order to get a sneak preview of their cargo, allowing them to more efficiently target and raid ships.

This bizarre discovery was detailed in Verizon's Data Breach Digest, published earlier this week. The report details how a major shipping conglomerate became suspicious when pirates began changing their tactics when commandeering a vessel. Instead of blindly rummaging through a targeted ship's cargo, they would search by bar code for highly valuable items and then flee—as if they had advance insight into a boat's contents.

Verizon's RISK Labs digital forensics team determined that this high-seas criminal network uploaded a malicious web shell onto a server running the company's content management system. The bad actors then used this compromised system to view key shipping and inventory data, including bills of lading.