APT31, an attack group affiliated with China, copied and used a National Security Agency (NSA) hacking tool years before Microsoft patched the vulnerability, Check Point Research reports.

Researchers have evidence revealing APT31 was able to access and clone a Windows hacking tool linked to the Equation Group, an operation discovered by Kaspersky in 2015. This group, described as one of the world’s most advanced, is believed to have been active since 2001 or earlier and is widely thought to have ties to the NSA’s Tailored Access Operations (TAO).

Both the American-affiliated and Chinese-affiliated versions of the hacking tool exploit CVE-2017-0005, a Windows privilege escalation vulnerability that was unknown at the time and previously attributed to APT31. The APT group has used its own version of the tool, which researchers call “Jian,” since at least 2015 and until Microsoft patched the vulnerability in 2017.

Jian was caught and reported to Microsoft by Lockheed Martin’s Computer Incident Response Team, indicating APT31 possibly used it against an American target. Some reports now indicate Lockheed Martin discovered the Chinese version of the tool used on a US-based network; however, it has not been confirmed which organization was affected. 

Now, researchers report Jian was actually a reconstructed version of an Equation Group tool. This tool, dubbed “EpMe,” is one of four different privilege escalation exploits included in the DanderSpritz attack framework, a post-exploitation framework used by the Equation Group that has a range of tools for persistence, reconnaissance, lateral movement, and bypassing security tools. EpMe dates back to 2013, years before APT31 was caught using it in the wild.

While they may exploit the same vulnerability, Check Point researchers point to “meaningful changes” between the original EpMe tool and the repurposed Jian tool. 

“EpMe, the exploit by Equation Group, is much more comprehensive and more professional,” says Itay Cohen, a Check Point senior security researcher. The entire DanderSpritz framework, of which EpMe is…