Sysjoker Malware got you down? Jamf’s got you covered

Jamf Threat Labs updates Jamf Protect to completely prevent SysJoker from threatening the security of your macOS fleet.

January 13 2022 by

Matthias Wollnik

Threat: SysJoker (backdoor)

Intezer published an in-depth analysis into a new cross-platform backdoor that was discovered in the wild. Objective-See also published a macOS-specific analysis.

It appears to be a targeted attack.

Affects: SysJoker affects macOS, Linux, and Windows (both Intel and Apple Silicon) devices.

Detected by: Jamf Protect detects SysJoker as part of the PlistDisguisedAsApple analytic.

Prevented by: Jamf Protect prevents SysJoker from running through Jamf Threat Prevention as of 1/12/2022.

Jamf Threat Defense prevents communication with all known C2 servers as of 1/12/2022.

IOCs (as published by Intezer with some additions):

Detection Content


Files and directories created on the machine:

  • /Library/MacOsServices
  • /Library/MacOsServices/updateMacOs
  • /Library/SystemNetwork
  • /Library/LaunchAgents/

Persistence: Creates persistence via LaunchAgent under the path /Library/LaunchAgents/



Files and directories created on the machine:

  • /.Library/
  • /.Library/SystemServices/updateSystem
  • /.Library/SystemNetwork
  • /.Library/log.txt

Persistence: Creates the cron job:

@reboot (/.Library/SystemServices/updateSystem)



Files and directories created on the machine:

  • C:\ProgramData\RecoverySystem
  • C:\ProgramData\RecoverySystem\
  • C:\ProgramData\RecoverySystem\msg.exe
  • C:\ProgramData\SystemData
  • C:\ProgramData\SystemData\igfxCUIService.exe
  • C:\ProgramData\SystemData\tempo1.txt
  • C:\ProgramData\SystemData\tempo2.txt
  • C:\ProgramData\SystemData\tempi1.txt
  • C:\ProgramData\SystemData\tempi2.txt
  • C:\ProgramData\SystemData\temps1.txt
  • C:\ProgramData\SystemData\temps2.txt
  • C:\ProgramData\SystemData\tempu.txt
  • C:\ProgramData\SystemData\microsoft_Windows.dll

Persistence: HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRun

Name: igfxCUIService Type: REG_SZ Data: “C:\ProgramData\SystemData\igfxCUIService.exe”


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