Latvian and NATO officials claim Russia was behind outage in Latvia’s mobile communications network before Russias war games in September code-named Zapad. According to intelligence experts the recent Zapad drills simulated an attack on all Baltic countries, it included the use of cyber weapons. The Russian army may have used communications jammer aimed towards Sweden from the Russia’s Baltic outpost Kaliningrad. The sophistication of the attacks leaves little doubt that there is some state-sponsorship involved. NATO cyber strategy is purely defensive.”]
Source: http://securityaffairs.co/wordpress/63918/cyber-warfare-2/zapad-drills.html