The U.S. State Department email system is back online after being shut down for several days following a cyber attack. A department spokesman says this hack is likely linked to an October data breach at the White House.
Officials say no classified data was compromised and that the attack did not affect any databases containing information about American citizens or foreign visa applicants. Only unclassified systems, Blackberry services and the department's public websites were disabled after the system intrusion.
Though the attack happened in late October, the State Department made the decision to disable the unclassified system in November.
State Department employees were unable to access the internet or reliably receive email from people outside the agency during the shutdown. Unclassified internal email was not affected. Currently, employees are still unable to access the internet from unclassified systems.
A spokesman originally said the system shutdown was just scheduled maintenance. Later, he said the shutdown was scheduled only after the breach was discovered.
U.S. officials decline to state who they think is responsible for the State Department or White House attack. Experts speculate that the hackers in both breaches were working for the Russian government.
In addition to the White House, the State Department also joins the United States Postal Service and the National Oceanic and Atmospheric Administration on a growing roster of hacked government agencies. Chinese government hackers are suspects in the USPS and NOAA attacks, though no official statements confirm this.
But pinpointing attacks to a particular organization or country is hard. Hackers usually route their attacks through web servers all over the world to obscure their activities.
Officials did not say how long hackers may have had access to any of these systems, but security improvements have been added.
The FBI is currently investigating the government data breaches.