Lithuania Targeted by Massive Russian Cyberattack Over Transit Blockade

A Russian hacker group appeared to hit Lithuania with a massive cyberattack as the Baltic nation continues to block the transit of European Union-sanctioned goods to the Russian exclave of Kaliningrad.

The Lithuanian Ministry of Defense confirmed the attack in a statement posted to Twitter on Monday, writing that state institutions had been targeted by an "intense DDoS attack." A DDoS, or distributed denial of service attack, is when an attacker attempts to overwhelm the servers of a given platform, service or website by flooding it with traffic.

Tensions between Lithuania and the Kremlin have escalated in recent days as Lithuania imposed EU sanctions on certain Russian goods, including steel and iron ore that were headed for Kaliningrad, a Connecticut-sized Russian exclave sandwiched between Lithuania and Poland.

Russia has largely been reliant on overland connections through Lithuania to transport goods to Kaliningrad, so Vilnius' refusal to allow such transport could threaten to worsen Russia's economic situation, which has already been affected by Western sanctions amid its widely condemned invasion of Ukraine.

Russian hackers hit Lithuania cyber attack
Russian hacker group Killnet has claimed responsibility for a cyberattack targeting Lithuania on Monday. Above, a person is pictured sitting with a laptop in Berlin on December 28, 2010. Sean Gallup/Getty Images

The situation has left the Baltic states, all members of the North Atlantic Treaty Organization (NATO), preparing for heightened tensions with Moscow, which warned Lithuania of "serious consequences" last week. Lithuania's defense ministry warned Monday that similar cyberattacks are likely to continue.

"It is likely that similar attacks will continue in the coming days, especially in the transport, energy and financial sectors. The most severe attacks now have been managed and services have been restored," a government statement said.

The attack targeted state institutions, transport institutions and media websites, Deputy Defence Minister Margiris Abukevicius said, according to Reuters. Some of the affected agencies included the State Tax Inspectorate and Migration Department, which were down for hours, the Associated Press reported.

The tax authority said the attack prompted them to stop their activities but that all data was safe, Reuters added.

Killnet, a Russian hacker group, claimed responsibility for the attack and said it was in response to Lithuania blocking the transit of the Russian goods, according to Reuters.

"The attack will continue until Lithuania lifts the blockade," a Killnet spokesperson told the news agency. "We have demolished 1,652 web resources. And that's just so far."

DDoS cyberattacks have previously been used by hackers amid the Russia-Ukraine war. In March, the online mapping and journalism tool Liveuamap, which had been showing the locations of Russian attacks in Ukraine, was hit by a similar attack, though it was not known who was responsible.

In February, U.S. Senator Mark Warner, a Virginia Democrat who chairs the Senate Intelligence Committee, warned of potential Russian cyberattacks. He said: "The two gravest immediate concerns I have is if Russia launches its full cyberattacks further against Ukraine, those cyberattacks, once you unleash them, [they have] no geographic boundary. We've already had reports that some of the cyberattacks launched against Ukraine have had results already in Latvia and Lithuania."