CyberStack

MITRE ATT&CK / Techniques / T1027

Obfuscated Files or Information

ID
T1027
Tactics
TA0005 Stealth
Platforms
ESXi, Linux, macOS, Network Devices, Windows
Data sources
Process Creation, File Creation, File Modification, Command Execution, Network Traffic Content, File Metadata, OS API Execution
Source
attack.mitre.org
MITRE last modified
12 Sep 2026

Adversaries may attempt to make an executable or file difficult to discover or analyze by encrypting, encoding, or otherwise obfuscating its contents on the system or in transit. This is common behavior that can be used across different platforms and the network to evade defenses.

Payloads may be compressed, archived, or encrypted in order to avoid detection. These payloads may be used during Initial Access or later to mitigate detection. Sometimes a user's action may be required to open and Deobfuscate/Decode Files or Information for 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.[3] Adversaries may also use compressed or archived scripts, such as JavaScript.

Portions of files can also be encoded to hide the plain-text strings that would otherwise help defenders with discovery.[4] Payloads may also be split into separate, seemingly benign files that only reveal malicious functionality when reassembled.[5]

Adversaries may also abuse Command Obfuscation to obscure commands executed from payloads or directly via Command and Scripting Interpreter. Environment variables, aliases, characters, and other platform/language specific semantics can be used to evade signature based detections and application control mechanisms.[6][7][8]

Sub-techniques (18)

Detection

Mitigations (4)

M1017 User Training

Ensure that a finite amount of ingress points to a software deployment system exist with restricted access for those required to allow and enable newly deployed software.

M1040 Behavior Prevention on Endpoint

On Windows 10+, enable Attack Surface Reduction (ASR) rules to prevent execution of potentially obfuscated payloads. [1]

M1047 Audit

Consider periodic review of common fileless storage locations (such as the Registry or WMI repository) to potentially identify abnormal and malicious data.

M1049 Antivirus/Antimalware

Anti-virus can be used to automatically detect and quarantine suspicious files. Consider utilizing the Antimalware Scan Interface (AMSI) on Windows 10+ to analyze commands after being processed/interpreted. [2]

Groups (19)

Software (142)

Showing 60 of 142. Full list on attack.mitre.org.

References

  1. win10_asr
  2. Microsoft AMSI June 2015
  3. Volexity PowerDuke November 2016
  4. Linux/Cdorked.A We Live Security Analysis
  5. Carbon Black Obfuscation Sept 2016
  6. FireEye Obfuscation June 2017
  7. FireEye Revoke-Obfuscation July 2017
  8. PaloAlto EncodedCommand March 2017