Mandiant has released a blog post detailing a cyber espionage campaign by a suspected North Korea-nexus group tracked as UNC2970. This group targets victims with the guise of job openings, masquerading as a recruiter for prominent companies.
What I found particularly interesting was UNC2970's use of a trojanized version of the open-source PDF reader SumatraPDF. They are not exploiting a vulnerability in SumatraPDF itself, but rather modifying the code to deliver their malware.
This technique highlights the growing threat posed by the software supply chain. Even when using open-source software, it is crucial to exercise caution and ensure the integrity of the software source.
I was also impressed by Mandiant's detailed breakdown of the infection chain, from luring the victim with an encrypted PDF file to deploying the MISTPEN backdoor.
This analysis provides valuable insights for security researchers and defenders to better understand UNC2970's tactics, techniques, and procedures (TTPs) and improve their defenses against this group.
I highly recommend reading Mandiant's blog post for the full analysis, including indicators of compromise (IOCs) and YARA rules for detection and response.
