- Tactics
- stealth
- Platforms
- ESXi, Linux, macOS, Windows
- Reference
- attack.mitre.org/techniques/T1140
Description
Adversaries may use Obfuscated Files or Information to hide artifacts of an intrusion from analysis. They may require separate mechanisms to decode or deobfuscate that information depending on how they intend to use it. Methods for doing that include built-in functionality of malware or by using utilities present on the system.
One such example is the use of certutil to decode a remote access tool portable executable file that has been hidden inside a certificate file.(Citation: Malwarebytes Targeted Attack against Saudi Arabia) Another example is using the Windows copy /b or type command to reassemble binary fragments into a malicious payload.(Citation: Carbon Black Obfuscation Sept 2016)(Citation: Sentinel One Tainted Love 2023)
Sometimes a user’s action may be required to open it for deobfuscation or decryption as part of User Execution. The user may also be required to input a password to open a password protected compressed/encrypted file that was provided by the adversary.(Citation: Volexity PowerDuke November 2016)
How GTK Cyber trains on this
GTK Cyber's Threat Hunting with Data Science course teaches you to build machine-learning detections for techniques like this across the MITRE ATT&CK framework, including the stealth tactic this technique falls under. Practitioner-led, focused on real detections, not memorizing technique IDs.
Related techniques
- T1006 — Direct Volume Access
- T1014 — Rootkit
- T1027 — Obfuscated Files or Information
- T1036 — Masquerading
- T1055 — Process Injection
- T1070 — Indicator Removal
- T1078 — Valid Accounts
- T1127 — Trusted Developer Utilities Proxy Execution
- T1134 — Access Token Manipulation
- T1197 — BITS Jobs
- T1202 — Indirect Command Execution
- T1205 — Traffic Signaling