Russian hacking groups launched DDoS attacks against Japanese logistics, shipbuilding companies, and government entities.

A distributed denial-of-service (DDoS) attack overwhelms a targeted server, network, or website with a massive flood of traffic, causing it to slow down or crash. This disrupts normal operations, making the service unavailable to legitimate users. Hackers often use networks of infected computers, known as botnets, to carry out these large-scale attacks.

The pro-Russian hacking groups who claimed responsibility for the attacks on Japanese targets are NoName057(16) and the Russian Cyber Army Team. Over half of the attacks, which started on Oct. 14, focused on logistics, shipbuilding, and manufacturing companies, according to network-monitoring firm Netscout.

The Russian group “has leveraged every attack capability of the DDoSia botnet, employing a wide range of direct-path attack vectors against multiple targets. As of this writing, approximately 40 targeted Japanese domains have been identified. On average, each domain is hit by three attack waves, utilizing four distinct DDoS attack vectors, utilizing approximately 30 different attack configurations to maximize attack impact,” Netscout said in its analysis.

Japan’s ruling Liberal Democratic Party (LDP) was also on the receiving end of these attacks. During a press conference,  Deputy Chief Cabinet Secretary Kazuhiko Aoki stated that Japan’s cyber agencies have taken necessary security measures and are actively investigating the attacks.

The hackers claimed their attacks were in response to a major joint military exercise that Japan and the U.S. plan to hold later this month on Japanese territory, including areas near Russia’s border. Russia has condemned the exercise, warning that it will take “adequate countermeasures” in response.

“We are punishing Russophobic Japan and reminding them that any actions against Russia can end badly,” NoName057(16) said in a statement.

Richard Hummel, director of threat intelligence at Netscout, also noted, “Japan had their elections last week, and the leader that took over is no fan of Russia and, in fact, has been very vocal about supporting Ukraine and sending aid.”