Anti-malware vendor Symantec is warning that a China-linked hacking group flagged as APT15 is targeting foreign affairs ministries in the Americas with a new backdoor named Graphican.
As part of an attack campaign running from late 2022 to early 2023, the threat actor used the new Graphican backdoor alongside multiple living-off-the-land tools.
Symantec noted that Graphican has the same functionality as Ketrican, a backdoor that APT15 used in previous attacks, but uses Microsoft Graph API to connect to OneDrive and retrieve command-and-control (C&C) information. Based on commands received from the C&C server, Graphican can create an interactive command line, create files, download files, and can create processes with hidden windows.
During the campaign, the company caught APT15 using variants of Ketrican that had a hardcoded C&C server with only some of these commands implemented. Other tools the group used in these attacks include the Ewstew backdoor, web shells, and publicly available tools such as Mimikatz, Pypykatz, Safetykatz, Lazagne, Quarks PwDump, SharpSecDump, K8Tools, and EHole.
These tools allow the attackers to steal email messages, dump Windows credentials and extract credentials from various applications, escalate privileges, scan for vulnerable machines, and exploit known flaws.
During the campaign, APT15 was observed exploiting CVE-2020-1472, a critical vulnerability in the Microsoft Windows Netlogon Remote Protocol (MS-NRPC) that was patched in August 2020.
Also known as Zerologon, the bug allows unauthenticated attackers to run a specially crafted application on a device on the network.
Likely sponsored by the Chinese government, APT15 is also tracked as Flea, KE3CHANG, Nickel, Playful Dragon, Royal APT, and Vixen Panda. According to Symantec, the group has been active since at least 2004 and is believed to be large and well-resourced.
The threat actor is specifically targeting governments, diplomatic missions, human rights organizations, embassies, and think-tanks in Central and South America, the Caribbean, Europe, and North America.
“The goal of the group does seem to be to gain persistent access to the networks of victims of interest for the purposes of intelligence gathering. Its targets in this campaign, of ministries of foreign affairs, also point to a likely geo-political motive behind the campaign,” Symantec added.