A Chinese threat actor was observed targeting both European diplomatic entities and the Tibetan community with the same strain of malware.
Tracked as APT TA413 and previously associated with LuckyCat and ExileRAT malware, the threat actor has been active for nearly a decade, and is believed to be responsible for a multitude of attacks targeting the Tibetan community.
In a report published Wednesday, Proofpoint’s security researchers revealed a link between COVID-19-themed attacks impersonating the World Health Organization (WHO) to deliver the “Sepulcher” malware to economic, diplomatic, and legislative entities within Europe and attacks on the Tibetan community that delivered LuckyCat-linked malware and ExileRAT.
Furthermore, a July campaign targeting Tibetan dissidents was attempting to deliver the same Sepulcher malware from the same infrastructure, with some of the employed email addresses previously used in attacks delivering ExileRAT, suggesting that both campaigns are the work of TA413.
“While best known for their campaigns against the Tibetan diaspora, this APT group associated with the Chinese state interest prioritized intelligence collection around Western economies reeling from COVID-19 in March 2020 before resuming more conventional targeting later this year,” Proofpoint notes.
Targeting European diplomatic and legislative entities and economic affairs and non-profit organizations, the March campaign attempted to exploit a Microsoft Equation Editor flaw to deliver the previously unidentified Sepulcher malware.
The July campaign was employing a malicious PowerPoint (PPSX) attachment designed to drop the same malware, and Proofpoint connected it to a January 2019 campaign that used the same type of attachments to infect victims with the ExileRAT malware.
What linked these attacks, Proofpoint reveals, was the reuse of the same email addresses, clearly suggesting that a single threat actor was behind all campaigns. The use of a single email address by multiple adversaries, over the span of several years, is unlikely, the researchers say.
“While it is not impossible for multiple APT groups to utilize a single operator account (sender address) against distinct targets in different campaigns, it is unlikely. It is further unlikely that this sender reuse after several years would occur twice in a four-month period between March and July, with both instances delivering the same Sepulcher malware family,” Proofpoint says.
The security researchers believe that the global crisis might have forced the attackers to reuse infrastructure, and that some OPSEC mistakes started to occur following re-tasking.
The Sepulcher malware can conduct reconnaissance on the infected host, supports reverse command shell, and reading and writing from/to file. Based on received commands, it can gather information about drives, files, directories, running processes, and services, can manipulate directories and files, moving file source to destination, terminate processes, restart and delete services, and more.
“The adoption of COVID-19 lures by Chinese APT groups in espionage campaigns was a growing trend in the threat landscape during the first half of 2020. However, following an initial urgency in intelligence collection around the health of western global economies in response to the COVID-19 pandemic, a return to normalcy was observed in both the targets and decoy content of TA413 campaigns,” Proofpoint notes.