Is Russia behind new GPS interference in Bulgaria?

GPS interference in Sofia, Bulgaria, began on dec. 12, 2024, and has continued at varying intensities. (Photo: GPSJam.org)

On Dec. 12, 2024, the European Union decided to include Bulgaria and Romania in the Schengen visa-free zone. On the same day, Bulgaria’s capital, Sofia, began experiencing interference with GPS signals. The interference, as reflected in aviation ADS-B systems and reported on GPSJam.org, continued through the new year and is ongoing as of this writing. 

While these two events may be entirely unrelated, Vladimir Putin has a history of using GPS jamming and spoofing to show his displeasure with his neighbors growing closer to the West.

• In 2022, after he warned Finland against trying to join NATO, the Finnish president met with U.S. president Biden. Russian jamming interfered with Finnish air traffic immediately thereafter.

• On Dec. 15, 2023, Poland activated a U.S. Aegis anti-missile system near its border with Kaliningrad, Russia. On the same day, Russia began jamming and spoofing GPS signals in northern Poland and parts of the Baltic. That interference persists to this day.

The interference in Sofia may be contributing to a prolonged Bulgarian political crisis. Politicians there have been struggling to form a new government since elections in October. Dec. 10 saw the beginning of a new attempt. Interference with GPS can undermine overall confidence in government systems and institutions — another of Putin’s goals for neighbors with whom he is displeased.

Another, though less likely, impact may be on Bulgaria’s electrical service. On Dec. 25, 2024, 20,000 households in western Bulgaria (Sofia is in the far west) lost electrical power and the outage continued for days. Many grid operators use GPS timing to help manage their systems. While press reports put the outages down to heavy snow and fallen trees, increased difficulty managing the grid might also be a factor.

Bulgaria’s GPS interference appears to be coming from somewhere in Sofia, not from Russian territory, as is the case in the Baltic. Yet Russia may still be involved, at least in a supporting role.

On Dec. 11, the news outlet Balken Insight reported on five Bulgarians being tried by the United Kingdom as Russian spies. It also said the Bulgarian interim prime minister was being urged to investigate alleged links between the case and top officials in Sofia.