Cyberattacks Cause 41 Defense Data Leaks Since 2024

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Cyberattacks were identified as the primary cause of 41 defense-related data leaks from 2024 through the current year. These incidents involved the theft of technical materials from defense contractors, with some cases remaining unverified due to missing system logs.

Data submitted to the National Assembly by the Defense Acquisition Program Administration shows a breakdown of the 41 cyberattack cases: 16 occurred in 2024, 14 in 2025, and 11 in the current year. Specific incidents include a 2024 hack of a LIG D&A contractor that leaked jamming and direction detection technology, and a 2025 breach of a contractor that exposed software specification documents for a military satellite communication system. It is not possible to determine from public information whether entire source code or military networks were compromised.

Fifteen data leak reports filed since 2021 could not be verified because of missing logs or human error. The administration cited the lack of preserved logs as a reason for the inability to confirm actual leaks. Logs are essential for identifying who accessed systems and when, and their absence hinders the investigation of intrusion paths and damage scope.

Two cyberattacks in 2024 and one in 2025 were estimated to be linked to North Korea, with file leaks confirmed in two of those cases. The administration used internet addresses and attack methods as the basis for these estimates, though it is not possible to attribute all defense data leaks to North Korea. Lawmakers have called for a thorough review of security management systems at both major defense companies and their contractors to protect national security technology.