Dissecting One of APT29's Fileless WMI and PowerShell Backdoors (POSHSPY) Written by: Matthew Dunwoody Mandiant has observed APT29 using a stealthy backdoor that we call POSHSPY. POSHSPY leverages two of the tools the group frequently uses: PowerShell and Windows Management Instrumentation (WMI). In the investigations Mandiant has conducted, it appeared that APT29 deployed POSHSPY as a secondary b