Re-opened Applications

Executive Summary

Re-opened Applications (T1547.007) is a MITRE ATT&CK technique associated with Persistence, Privilege Escalation. Adversaries may modify plist files to automatically run an application when a user logs in.

Why Attackers Use It

Attackers use Re-opened Applications because it provides a reliable way to advance their objective within the Persistence, Privilege Escalation tactic, often with a favorable balance of impact versus detectability on macOS environments. Defenders should assess this behavior in the context of the affected platform and adjacent activity rather than treating it as a standalone indicator.

MITRE Description

Adversaries may modify plist files to automatically run an application when a user logs in. When a user logs out or restarts via the macOS Graphical User Interface (GUI), a prompt is provided to the user with a checkbox to "Reopen windows when logging back in".(Citation: Re-Open windows on Mac) When selected, all applications currently open are added to a property list file named <code>com.apple.loginwindow.[UUID].plist</code> within the <code>~/Library/Preferences/ByHost</code> directory.(Citation: Methods of Mac Malware Persistence)(Citation: Wardle Persistence Chapter) Applications listed in this file are automatically reopened upon the user’s next logon.

Adversaries can establish Persistence by adding a malicious application path to the <code>com.apple.loginwindow.[UUID].plist</code> file to execute payloads when a user logs in.

Attack Flow

1. Attacker gains the prerequisite access or context described below.
2. Attacker executes Re-opened Applications to achieve its tactical objective (Persistence, Privilege Escalation).
3. Resulting access/data/effect is leveraged to advance the broader attack chain (see Related Techniques).

Prerequisites

• Platform(s): macOS
• ATT&CK does not define one universal permission requirement for this technique. Establish the required access from the observed implementation and affected platform.

Common Tools

• Tool attribution is implementation-specific. Use ATT&CK procedure examples and local telemetry to identify the binaries, services, scripts, accounts, or cloud resources involved.

Commands

No universal command represents Re-opened Applications. Capture the exact command line, arguments, parent process, account, host, and execution time from the investigated environment; do not operationalize unverified examples.

Network Traffic

• Network observability is implementation-dependent. Review DNS, proxy, firewall, flow, authentication, and packet telemetry around the activity window, then correlate remote endpoints and protocol behavior with host evidence.

Windows Events

Sysmon Events

Detection Opportunities

No MITRE detection guidance published for this technique.

Relevant ATT&CK Data Sources: N/A

Sigma Rules

A universal Sigma rule would create unreliable results because this technique has no single guaranteed observable. Build detection logic from a documented behavior and supported data source, scope it to the affected platform, and validate it against benign administrative activity before deployment.

Splunk Queries

Start with the data sources named in the detection section. Scope searches by asset, identity, and time window; correlate the primary behavior with preceding access and subsequent actions. A portable query is intentionally not provided where the technique lacks a universal schema or observable.

Investigation Workflow

1. Confirm that the observed behavior is consistent with Re-opened Applications and rule out expected administrative or application activity.
2. Establish the first-seen time, initiating identity, source system, target system, and affected resources.
3. Collect relevant host, identity, network, cloud, and application telemetry for the surrounding time window.
4. Correlate parent and child activity, remote connections, file or configuration changes, and related ATT&CK techniques.
5. Determine scope by searching for the same observable across peer assets and identities.
6. Preserve volatile evidence and record confidence, assumptions, and telemetry gaps before containment.

Containment

1. Isolate affected host(s)/account(s) identified during investigation.
2. Revoke or rotate any credentials/tokens potentially exposed.
3. Apply the mitigations listed below where not already enforced.
4. Validate no related techniques (see Related Techniques) were chained against the same asset.

Mitigation

• M1042 -- Disable or Remove Feature or Program: Disable or remove unnecessary and potentially vulnerable software, features, or services to reduce the attack surface and prevent abuse by adversaries.
• M1017 -- User Training: User Training involves educating employees and contractors on recognizing, reporting, and preventing cyber threats that rely on human interaction, such as phishing, social engineering, and other manipulative techniques.

Related Techniques

• T1547