Trend Micro summarized the 3CX Desktop App compromise as a multi-stage attack against the Electron Windows and macOS clients used by 3CX customers worldwide. The compromised MSI starts with benign 3CXDesktopApp.exe loading trojanized ffmpeg.dll, which reads encrypted shellcode from d3dcompiler_47.dll after FE ED FA CE markers and decrypts it with the RC4 key 3jB(2bsG#@c7. The shellcode reaches the removed IconStorages GitHub repository, retrieves ICO files containing Base64/AES-GCM encrypted C2 strings, and then contacts listed command-and-control domains to fetch possible final payloads. The source notes a seven-day-plus sleep timestamp mechanism, affected versions from 3CX’s advisory, and risk from the software’s large enterprise deployment base.