Complete technique description
Adversaries may modify applications installed on a device to establish persistent access to a victim. These malicious modifications can be used to make legitimate applications carry out adversary tasks when these applications are in use.
There are multiple ways an adversary can inject malicious code into applications. One method is by taking advantages of device vulnerabilities, the most well-known being Janus, an Android vulnerability that allows adversaries to add extra bytes to APK (application) and DEX (executable) files without affecting the file's signature. By being able to add arbitrary bytes to valid applications, attackers can seamlessly inject code into genuine executables without the user's knowledge.[Guardsquare Janus]
Adversaries may also rebuild applications to include malicious modifications. This can be achieved by decompiling the genuine application, merging it with the malicious code, and recompiling it.[CheckPoint Agent Smith]
Adversaries may also take action to conceal modifications to application executables and bypass user consent. These actions include altering modifications to appear as an update or exploiting vulnerabilities that allow activities of the malicious application to run inside a system application.[CheckPoint Agent Smith]
Official technique definition · Open in the interactive matrix
Detection telemetry and configuration
These contracts are selected through exact technique-to-data-component relationships or explicitly labelled planning overrides. Configure a collector at the relevant observation point; a telemetry name alone is not coverage.
Application Permission · source-mapped
DC0114 collection page — Compare manifest declarations with runtime granted state using authorized package inspection and own-app permission checks.
Providers and collection configuration
- Android logcat: Permitted logs from a consented test device/emulator; output depends on build, permissions and instrumentation.
- Android dumpsys: Point-in-time service/package state on an authorized development device.
- Instrumented test application: Own-app permission, API and state callbacks; not universal visibility into other apps.
- Use a disposable emulator or owned development device with approved debugging. Record OS/API level, app version and instrumentation privileges.
- Collect only relevant logcat buffers/tags and service snapshots; add explicit own-app instrumentation for events absent from OS logs.
- Forward sanitized logs and compare before/after state. Remove test data and revoke debugging access after the lab session.
Required normalized fields: package, permission, declared, granted.
adb shell dumpsys package test.example.lab
Read-only snapshot on a consented debug device. Replace the example package with your owned test app. Output and access vary by Android build; this is not a permission-request event stream.
Illustrative collection event
Project-normalized synthetic JSON, not a native provider log, captured event, attack verdict or validated detection. A parser/adapter is required for a real SIEM. Example names, IPs and values are fictional.
{
"schema": "1200km.telemetry.example.v1",
"synthetic": true,
"timestamp": "2026-09-27T12:00:00Z",
"telemetry_id": "DC0114",
"collector": "illustrative-lab-collector",
"observation": {
"package": "test.example.lab",
"permission": "android.permission.CAMERA",
"declared": true,
"granted": false
}
}
Visibility limits: Android tooling does not imply iOS coverage. Standard mobile apps cannot observe all other apps or protected OS internals; MDM status is not full API, filesystem or content telemetry.
Application State · source-mapped
DC0123 collection page — Instrument the owned app lifecycle and corroborate permitted service snapshots; distinguish app events from inferred gateway activity.
Providers and collection configuration
- Android logcat: Permitted logs from a consented test device/emulator; output depends on build, permissions and instrumentation.
- Android dumpsys: Point-in-time service/package state on an authorized development device.
- Instrumented test application: Own-app permission, API and state callbacks; not universal visibility into other apps.
- Use a disposable emulator or owned development device with approved debugging. Record OS/API level, app version and instrumentation privileges.
- Collect only relevant logcat buffers/tags and service snapshots; add explicit own-app instrumentation for events absent from OS logs.
- Forward sanitized logs and compare before/after state. Remove test data and revoke debugging access after the lab session.
Required normalized fields: package, state_before, state_after, source.
Illustrative collection event
Project-normalized synthetic JSON, not a native provider log, captured event, attack verdict or validated detection. A parser/adapter is required for a real SIEM. Example names, IPs and values are fictional.
{
"schema": "1200km.telemetry.example.v1",
"synthetic": true,
"timestamp": "2026-09-27T12:00:00Z",
"telemetry_id": "DC0123",
"collector": "illustrative-lab-collector",
"observation": {
"package": "test.example.lab",
"state_before": "background",
"state_after": "foreground",
"source": "own_app_callback"
}
}
Visibility limits: Android tooling does not imply iOS coverage. Standard mobile apps cannot observe all other apps or protected OS internals; MDM status is not full API, filesystem or content telemetry.
File Creation · source-mapped
DC0039 collection page — Scope Sysmon FileCreate (11) to the lab directory; retain the process and file path. Differentiate creation/overwrite if the sensor can.
Providers and collection configuration
- Microsoft Sysmon: Windows event-based collection; enable the event types needed below.
- Linux Audit: Linux alternative for supported system-call and file events; different semantics and fields.
- Apple Endpoint Security clients: macOS alternative where the subscribed event exists; requires an entitled, approved client, not an iOS collector.
- On a disposable Windows host, review the installed Sysmon schema and current configuration; merge scoped event filters into the existing policy rather than replacing it.
- Forward Microsoft-Windows-Sysmon/Operational to the lab collector. Preserve event ID, timestamp, computer, process identifiers and the original event.
- For Linux or macOS, select the equivalent sensor separately and test its emitted fields; a Windows event ID does not transfer across platforms.
Required normalized fields: process_id, path, action, size_bytes.
Illustrative collection event
Project-normalized synthetic JSON, not a native provider log, captured event, attack verdict or validated detection. A parser/adapter is required for a real SIEM. Example names, IPs and values are fictional.
{
"schema": "1200km.telemetry.example.v1",
"synthetic": true,
"timestamp": "2026-09-27T12:00:00Z",
"telemetry_id": "DC0039",
"collector": "illustrative-lab-collector",
"observation": {
"process_id": 4200,
"path": "C:\\Lab\\demo.txt",
"action": "create",
"size_bytes": 64
}
}
Visibility limits: Event filtering and sensor versions change coverage. High-volume image-load and process-access collection needs tuning; endpoint events alone do not establish intent.
OS API Execution · source-mapped
DC0021 collection page — Use an approved EDR trace or instrument the owned lab process at selected APIs. Define API name, caller, sanitized arguments and return status.
Providers and collection configuration
- Enable the application audit category or instrument the owned lab application at the authorization/action boundary.
- Define a schema with timestamp, service, actor, object, action, result and correlation ID. Export structured records through an authenticated collector.
- Redact secrets and personal content, separate audit from debug logs, set retention and verify delivery during rotation/restart.
Required normalized fields: process_id, api, path, result.
Illustrative collection event
Project-normalized synthetic JSON, not a native provider log, captured event, attack verdict or validated detection. A parser/adapter is required for a real SIEM. Example names, IPs and values are fictional.
{
"schema": "1200km.telemetry.example.v1",
"synthetic": true,
"timestamp": "2026-09-27T12:00:00Z",
"telemetry_id": "DC0021",
"collector": "illustrative-lab-collector",
"observation": {
"process_id": 4200,
"api": "CreateFileW",
"path": "C:\\Lab\\demo.txt",
"result": "success"
}
}
Visibility limits: Debug output is not necessarily a durable audit trail. Application developers must emit the relevant event; installing a log pipeline does not make an absent event exist.
Simulation design and documented procedures
Atomic evidence: no compatible candidate in this snapshot. Live lab status: not run for these imported procedures.
Use owned test devices or emulators, disposable app accounts and test data. Verify platform/version instrumentation; desktop test procedures do not establish mobile coverage.
No compatible Atomic procedure is present in this pinned evidence set. Technical feasibility has not been ruled out. A custom procedure must define the behavior, target, collection point, success observable and rollback before execution.
Technique-specific experiment contract
- Choose one procedure implementing T1577 Compromise Application Executable; identify the observable behavior in the source definition, not just its tactic.
- Record exact target, tool/version, inputs, privileges, network limits and approval. Never run an imported default target automatically.
- Enable the collection sources above and verify a benign baseline reaches the detector.
- Run only the approved isolated scenario; capture native events and an independent behavior observable.
- Evaluate the exact rule/model, restore the lab, and preserve configuration, event hashes, alerts, controls and misses.