Hackers from China broke into the US federal weather system in late September, according to a report in the Washington Post.
The hack targeted a National Oceanic and Atmospheric Administration web server and affected four NOAA web sites that process and coordinate data and images from satellites that track storms, temperature, and other weather systems.
In order to the respond to the breach, government officials told the Post that cybersecurity teams had to "seal off data vital to disaster planning, aviation, shipping and scores of other crucial uses."
This temporarily compromised the accuracy of some National Weather Service forecasts and may have slightly skewed long-range weather forecasts.
Officials also told the Post that NOAA didn't immediately follow procedures requiring any government agency to notify certain officials in the event of a security breach.
This caused NOAA to perform unscheduled maintenance in order to restore security.
In response to a request for information from Business Insider, NOAA spokesperson Scott Smullen provided this statement:
In recent weeks, four NOAA websites were compromised by an internet-sourced attack. NOAA staff detected the attacks and incident response began immediately. Unscheduled maintenance was performed by NOAA to mitigate the attacks. The unscheduled maintenance impacts were temporary and all services have been fully restored. These effects did not prevent us from delivering forecasts to the public. The investigation is continuing with the appropriate authorities and we cannot comment further.
WaPo notes that the purpose of the hack itself was most likely an attempt try to find an opening into US government agency computer systems by exploiting a not-very-secure entry point. Although NOAA's web sites are protected, one person who was familiar with those systems described their security to the Post as "just a screen door."
Through a Freedom of Information Act request, the Post uncovered a previously unreleased report from July that described NOAA's security as highly vulnerable.
The confirmation of this hack follows a report from Monday that China may have hacked the US Postal Service, which compromised the personal information of 800,000 employees.