SSFileCopySender Executed as Root

Last updated 4 days ago on 2026-09-18
Created a month ago on 2026-08-19

About

Identifies execution of the macOS Screen Sharing file-copy helper SSFileCopySender with root UID/GID attributes (0 80). Under the native Apple authentication path this helper runs in the connecting user's context; execution as root is anomalous and consistent with pre-authentication exploitation of the Screen Sharing service (CVE-2026-65400), where a flawed SRP validation path lets an unauthenticated attacker reach privileged file operations. Note that the 0/80 UID/GID pair reflects only initial exploitation attempts and can be evaded once an attacker enumerates another local account. It is advisable to treat this as a tripwire and pair it with the SSFileCopyReceiver Writing to Common Persistence Locations rule coverage.
Tags
Domain: EndpointOS: macOSUse Case: Threat DetectionUse Case: VulnerabilityTactic: Initial AccessData Source: Elastic DefendRule Type: ES|QLPlatform: macOSVuln: CVE-2026-65400Language: esql
Severity
medium
Risk Score
47
MITRE ATT&CK™

Initial Access (TA0001)(external, opens in a new tab or window)

Privilege Escalation (TA0004)(external, opens in a new tab or window)

License
Elastic License v2(external, opens in a new tab or window)

Definition

Integration Pack
Prebuilt Security Detection Rules
Related Integrations

endpoint(external, opens in a new tab or window)

Query
text code block:
from logs-endpoint.events.process-* METADATA _id, _index, _version | WHERE host.os.type == "macos" AND event.type == "start" AND process.name == "SSFileCopySender" AND KQL(""" process.args : "0" AND process.args : "80" """) | KEEP _id, _version, _index, @timestamp, data_stream.namespace, host.name, host.id, user.id, user.name, process.name, process.entity_id, process.parent.name, process.command_line | SORT @timestamp DESC | LIMIT 100

Install detection rules in Elastic Security

Detect SSFileCopySender Executed as Root in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(external, opens in a new tab or window).