Chinese state-backed hackers have recently targeted South Korean entities involved in deploying a U.S. missile-defense system, says an American cybersecurity firm, despite Beijing’s denial of retaliation against Seoul over the issue.
In recent weeks, two cyberespionage groups that the firm linked to Beijing’s military and intelligence agencies have launched a variety of attacks against South Korea’s government, military, defense companies and a big conglomerate, John Hultquist, director of cyberespionage analysis at FireEye Inc., said in an interview.
The California-based firm, which counts South Korean agencies as clients, including one that oversees internet security, wouldn’t name the targets.
While FireEye and other cybersecurity experts say Chinese hackers have long targeted South Korea, they note a rise in the number and intensity of attacks in the weeks since South Korea said it would deploy Terminal High-Altitude Area Defense, or Thaad, a sophisticated missile-defense system aimed at defending South Korea from a North Korean missile threat.
China opposes Thaad, saying its radar system can reach deep into its own territory and compromise its security. South Korea and the U.S. say Thaad is purely defensive. The first components of the system arrived in South Korea last month and have been a key issue in the current presidential campaign there.
One of the two hacker groups, which FireEye dubbed Tonto Team, is tied to China’s military and based out of the northeastern Chinese city of Shenyang, where North Korean hackers are also known to be active, said Mr. Hultquist, a former senior U.S. intelligence analyst. FireEye believes the other, known as APT10, may be linked to other Chinese military or intelligence units.
China’s Ministry of Defense said this week Beijing has consistently opposed hacking, and that the People’s Liberation Army “has never supported any hacking activity.” China has said it is itself a major hacking victim but has declined to offer specifics.
Mr. Hultquist said the two hacking groups gained access to their targets’ systems by using web-based intrusions, and by inducing people to click on weaponized email attachments or compromised websites. He declined to offer more specific details.
Mr. Hultquist added that an error in one of the group’s operational security provided FireEye’s analysts with new information about the group’s origins.
South Korea’s Ministry of Foreign Affairs said last month that its website was targeted in a denial-of-service attack—one in which a flood of hacker-directed computers cripple a website—that originated in China.
A spokesman said that “prompt defensive measures” ensured that the attacks weren’t effective, adding that it was maintaining an “emergency service system” to repel Chinese hackers.
The ministry this week declined to comment further, or to say which cybersecurity firm it had employed or whether he thought the attacks were related to Thaad.
Another cybersecurity company, Russia’s Kaspersky Lab ZAO, said it observed a new wave of attacks on South Korean targets using malicious software that appeared to have been developed by Chinese speakers starting in February.
The attackers used so-called spear-phishing emails armed with malware hidden in documents related to national security, aerospace and other topics of strategic interest, said Park Seong-su, a senior global researcher for Kaspersky. The company typically declines to attribute cyberattacks and said it couldn’t say if the recent ones were related to Thaad.
The two hacking groups with alleged ties to Beijing have been joined by other so-called hacktivists—patriotic Chinese hackers acting independently of the government and using names like the “Panda Intelligence Bureau” and the “Denounce Lotte Group,” Mr. Hultquist said.
South Korea’s Lotte Group has become a particular focus of Chinese ire after the conglomerate approved a land swap this year that allowed the government to deploy a Thaad battery on a company golf course.
Last month, just after the land swap was approved, a Lotte duty-free shopping website was crippled by a denial-of-service attack, said a company spokeswoman, who added that its Chinese website had been disrupted with a virus in February. She declined to comment on its source.
China’s Ministry of Foreign Affairs didn’t respond to questions about the website attacks. The ministry has previously addressed Lotte’s recent troubles in China by saying that the country welcomes foreign companies as long as they abide by Chinese law.
The U.S. has also accused Chinese state-backed hacking groups of breaking into government and commercial networks, though cybersecurity firms say such activity has dropped since the two nations struck a cybersecurity deal in 2015. The two Chinese hacking groups named by FireEye are suspected of previous cyberattacks.
FireEye linked Tonto Team to an earlier state-backed Chinese hacking campaign, identified by Tokyo-based cybersecurity firm Trend Micro Inc. in 2012, which focused on South Korea’s government, media and military. Trend Micro declined to comment.
Two cybersecurity reports this month accused APT10 of launching a spate of recent attacks around the globe, including on a prominent U.S. trade lobbying group.
One of those reports, jointly published by PricewaterhouseCoopers LLP and British weapons maker BAE Systems, said the Chinese hacker collective has recently grown more sophisticated, using custom-designed malware and accessing its targets’ systems by first hacking into trusted third-party IT service providers.
Because of the new scrutiny from that report, FireEye said in a recent blog post that APT10 was likely to lay low, though in the longer run, it added, “we believe they will return to their large-scale operations, potentially employing new tactics, techniques and procedures.”