A China-linked state-sponsored group has started adopting ransomware tactics and appears to be pursuing financial gains against companies that otherwise would not be considered targets of espionage, according to an analysis of a spate of ransomware attacks published on Jan. 4.
The attacks targeted at least five online gambling companies in the first half of 2020 and had the hallmarks of the APT27 group, also known as Emissary Panda, according to the analysis written by Security Joes and Profero, two boutique incident response firms that aided the firms in defending against and cleaning up after the attacks.
The financial motive and use of ransomware would be a departure for China-linked state-sponsored hackers, which have typically focused on espionage targets, says Omri Segev Moyal, CEO of Profero.
"In this particular case, it was 100% for monetization because they were not encrypting files of an intelligence organization or deleting them to hide their tracks," Moyal says. "They went directly to the crown jewels, they didn't exfiltrate any sensitive data, and they just encrypted them using BitLocker. It was a high-stakes cash-out against specific companies."
The cyber-operations groups of other countries have occasionally encrypted data. Attackers linked to Iran have deleted hard drives at the Saudi Arabian national oil conglomerate Saudi Aramco. And Russia is widely considered to be the source of the NotPetya wiper attack against Ukrainian firms, which appeared to be a ransomware attack but quickly spread and damaged operations at businesses worldwide.
Some Russian hacking groups have deployed ransomware, but North Korea is the best-known nation-state using ransomware to regularly siphon funds from global companies.
While the report hedged the attribution of the attacks — vacillating between remarking on similarities to a group known as Winnti and to APT27 — Moyal concludes that all evidence leads back to a China-backed group with "100%" certainty.
"It is really hard to tell if it is a Chinese military agency or it is one of the subcontractors working for the government," he says. "At the end of the day, it is the same people. It may be the same subcontractor or the same group or the same people."
APT27 would not be the first Chinese espionage group to shift to financially motivated attacks. In March 2020, cybersecurity firm FireEye published an extensive analysis of a group, APT41, that also appeared to be blending cyber espionage and personal financial gain. The group used exploits for virtual private network (VPN) appliances and virtual desktops to hit companies in a variety of industries in at least 20 countries, including the United States, but not China or Russia.
"[We assess] with high confidence that APT41 is a prolific cyber threat group that carries out Chinese state-sponsored espionage activity in addition to financially motivated activity potentially outside of state control," FireEye stated in a subsequent report. "Activity traces back to 2012 when individual members of APT41 conducted primarily financially motivated operations focused on the video game industry before expanding into likely state-sponsored activity."
In September, the US charged five members of the APT41 group with hacking.
In the latest attacks, the APT27 group also set itself apart because it does not use common ransomware programs but instead uses the native encryption on many Windows machines, BitLocker, to scramble the data on infected machines. BitLocker is a common way to encrypt data and hard drives on computers running Windows Professional.
"The unique thing about the incident here is that they didn't use any specialized or commercial ransomware for deniability, such as Maze or Ryuk," Profero's Moyal says. "Here, they directly used, via DRBControl, BitLocker commands directly from the payload."
The malware installed on compromised systems allows a small slate of commands, including gathering system information, changing the communications protocol, pinging the command-and-control server, and loading additional malware onto the machine.
Moyal has faith in the report's attribution of the attack, but the reasons behind the shift to financially motivated attacks continue to be a mystery, he says.
"It happened during the peak of COVID-19 — almost every place in the world was under lockdown," he says. "Why did it change? Did they have something against gaming companies? Or was it a rogue member of the group looking for cash? Or it may be the government looking for untraceable funds? We don't know."