Standaloneupdaterdaemon May 2026

StandaloneUpdaterDaemon is a legitimate background process on macOS specifically associated with Microsoft OneDrive. It functions as a "daemon"—a faceless task that runs continuously to handle updates for Microsoft applications without requiring manual user intervention. What is StandaloneUpdaterDaemon?

Part 3: Normal vs. Malicious Behavior – How to Tell the Difference

Legitimate Behavior (Green Flags)

• Low Resource Usage: When idle, it consumes 0-2% CPU and under 50 MB of RAM.
• Scheduled Activity: It wakes up once every 6-24 hours, checks an update server, and goes back to sleep.
• Located in a Verified Directory: Typically found in:
  • Limits network usage (e.g., 10% of available bandwidth, absolute KB/s limit).
  • CPU/IO priority set to "low" or "idle" to avoid interfering with the main application or other processes.

  Notification: In some configurations, it can provide notifications about available updates or the completion of update installations. standaloneupdaterdaemon

  Background Download & Installation – Upon detecting an update, the daemon downloads the package in chunks (using delta patching if supported). To minimize disruption, it waits for the system to be idle (low CPU usage, no active full-screen applications). Finally, it applies the update, which may require restarting the associated application or, in rare cases, the entire system. Low Resource Usage: When idle, it consumes 0-2%

  4.4 Applier (Atomic Update Engine)

  • Backup phase: Copies current working files to a snapshot directory.
  • Apply phase: Uses copy-on-write or symlink swap (e.g., /usr/bin/app -> /opt/app-v2/).
  • Commit phase: On success, updates state and removes old backup.
  • Two-phase commit: Changes are written to a staging area; only final rename() or ln -sf makes them live.

  Location: The executable is typically found within the OneDrive app bundle at:/Applications/OneDrive.app/Contents/StandaloneUpdaterDaemon.xpc/Contents/MacOS/StandaloneUpdaterDaemon. Limits network usage (e