Within the output of command sudo sfltool dumpbtm, in addition to records for UID 0/501/502/..., at the top of the output, there are also records for UID -2 listed. ======================== Records for UID -2 : FFFFEEEE-DDDD-CCCC-BBBB-AAAAFFFFFFFE ======================== ServiceManagement migrated: true SharedFileList migrated: false LaunchServices registered: false Items: #1: UUID: FC60A3EA-E4B0-4D8C-BA07-1C6E2DF3AA52 Name: (null) Developer Name: (null) Type: developer (0x20) Flags: [ ] (0) Disposition: [disabled, allowed, visible, not notified] (0x2) Identifier: Unknown Developer URL: (null) Generation: 0 Embedded Item Identifiers: #1: 16.com.microsoft.teams.TeamsUpdaterDaemon But a uid with -2 should be invalid, and the guid FFFFEEEE-DDDD-CCCC-BBBB-AAAAFFFFFFFE followed looks also strange.