Gustavo Palazolo and Ghanashyam Satpathy
Summary
On May 27, 2022, a Microsoft Office document was submitted from Belarus to VirusTotal, using a novel method to deliver its payload. This new technique was identified as a Zero-Day RCE (Remote Code Execution) vulnerability in Microsoft Support Diagnostic Tool (MSDT), which is now being tracked as CVE-2022-30190. As of this writing, it affects only Windows computers running with MSDT URI protocol enabled.
The methods of execution and net result of this vulnerability continue to expand as it gains more attention, similar to what we observed with Log4j. CVE-2022-30190 is also being called Follina, because the sample uploaded to VirusTotal references 0438, which is the area code for Follina in Italy.
This vulnerability does not require any macros, which are now disabled by default on files downloaded from the internet. The exploit can be achieved through crafted URLs that use the ms-msdt URL protocol, which will eventually load and execute code. The attack surface for MSDT Protocol in Office is also quite large. Furthermore, the document spotted on May 27 is using Living-off-the-Land techniques by abusing “