Japan Government Websites Hit by Hackers; Pro-Russian Group Suspected

Federal prosecutors alleged an employee affiliated with Russia’s defense ministry installed 'back doors' in computer systems and deployed malware aimed at crippling the safety of energy facilities. (Dreamstime/TNS)

Japan is investigating a series of cyberattacks on government websites, for which a pro-Russian hacker group has reportedly claimed responsibility, according to local reports.

Japan’s e-Gov website—which provides administrative information—and several other ministry websites were temporarily inaccessible from about midday on Sept. 6 before being restored later that day, the nation’s digital agency said on Sept. 7. The agency stated that the attacks didn’t compromise any personal information, local media Asahi Shimbun reported.

Pro-Russian hacker group “Killnet” claimed responsibility for the attacks via its social media account, saying that it was “revolting against Japan’s militarism,” Kyodo News reported.

Chief Cabinet Secretary Hirokazu Matsuno said that authorities are investigating the cause of the website access failure and whether the group was involved in the attacks. Japanese authorities suspect that hackers used a distributed denial-of-service (DDoS) attack to overload websites with a large amount of data and blocked users from accessing the websites.

Killnet Listed on CISA’s Advisory

Killnet is a pro-Russian group that has targeted nations that have supported Ukraine amid the ongoing Russian invasion of Ukraine. It’s among Russian-aligned cybercrime groups that “pose a threat to critical infrastructure organizations,” the U.S. Cybersecurity and Infrastructure Security Agency (CISA) said in an advisory.

CISA cited a March incident in which Killnet claimed responsibility for carrying out a DDoS attack against a U.S. airport after the United States provided material support to Ukraine.

Killnet also claimed credit for a cyberattack on Lithuania’s public and private websites in June, after the nation restricted the transit of steel and ferrous metals as part of European Union sanctions against Russia.

Japan has imposed a slew of sanctions on Russia over the war in Ukraine, including sanctions targeting Putin and several other Russian leaders. It also restricted exports of certain goods to the country and banned certain Russian banks from the SWIFT global interbank network.

Japan also supplied Ukraine with defense equipment, such as bulletproof vests and helmets, and pledged to accept Ukrainian refugees even if they have no relatives in Japan.