Input Injection

Executive Summary

Input Injection (T1674) is a MITRE ATT&CK technique associated with Execution. Adversaries may simulate keystrokes on a victim’s computer by various means to perform any type of action on behalf of the user, such as launching the command interpreter using keyboard shortcuts, typing an inline script to be executed, or interacting directly with a GUI-based application.

Why Attackers Use It

Attackers use Input Injection because it provides a reliable way to advance their objective within the Execution tactic, often with a favorable balance of impact versus detectability on Windows, macOS, Linux 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 simulate keystrokes on a victim’s computer by various means to perform any type of action on behalf of the user, such as launching the command interpreter using keyboard shortcuts, typing an inline script to be executed, or interacting directly with a GUI-based application. These actions can be preprogrammed into adversary tooling or executed through physical devices such as Human Interface Devices (HIDs).

For example, adversaries have used tooling that monitors the Windows message loop to detect when a user visits bank-specific URLs. If detected, the tool then simulates keystrokes to open the developer console or select the address bar, pastes malicious JavaScript from the clipboard, and executes it - enabling manipulation of content within the browser, such as replacing bank account numbers during transactions.(Citation: BleepingComputer BackSwap)(Citation: welivesecurity BackSwap)

Adversaries have also used malicious USB devices to emulate keystrokes that launch PowerShell, leading to the download and execution of malware from adversary-controlled servers.(Citation: BleepingComputer USB)

Attack Flow

1. Attacker gains the prerequisite access or context described below.
2. Attacker executes Input Injection to achieve its tactical objective (Execution).
3. Resulting access/data/effect is leveraged to advance the broader attack chain (see Related Techniques).

Prerequisites

• Platform(s): Windows, macOS, Linux
• 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 Input Injection. 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 Input Injection 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

• M1034 -- Limit Hardware Installation: Prevent unauthorized users or groups from installing or using hardware, such as external drives, peripheral devices, or unapproved internal hardware components, by enforcing hardware usage policies and technical controls.
• M1038 -- Execution Prevention: Prevent the execution of unauthorized or malicious code on systems by implementing application control, script blocking, and other execution prevention mechanisms.

Related Techniques

No related techniques mapped.