MITRE ATT&CK Technique
T1027Obfuscated Files or Information
- First Reported
- Jul 17, 2017
- Latest Reported
- Nov 7, 2026
Official Description
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](https://attack.mitre.org/techniques/T1140) for [User Execution](https://attack.mitre.org/techniques/T1204). 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) 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.(Citation: Linux/Cdorked.A We Live Security Analysis) Payloads may also be split into separate, seemingly benign files that only reveal malicious functionality when reassembled.(Citation: Carbon Black Obfuscation Sept 2016)
Adversaries may also abuse [Command Obfuscation](https://attack.mitre.org/techniques/T1027/010) to obscure commands executed from payloads or directly via [Command and Scripting Interpreter](https://attack.mitre.org/techniques/T1059). Environment variables, aliases, characters, and other platform/language specific semantics can be used to evade signature based detections and application control mechanisms.(Citation: FireEye Obfuscation June 2017)(Citation: FireEye Revoke-Obfuscation July 2017)(Citation: PaloAlto EncodedCommand March 2017)
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](https://attack.mitre.org/techniques/T1140) for [User Execution](https://attack.mitre.org/techniques/T1204). 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) 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.(Citation: Linux/Cdorked.A We Live Security Analysis) Payloads may also be split into separate, seemingly benign files that only reveal malicious functionality when reassembled.(Citation: Carbon Black Obfuscation Sept 2016)
Adversaries may also abuse [Command Obfuscation](https://attack.mitre.org/techniques/T1027/010) to obscure commands executed from payloads or directly via [Command and Scripting Interpreter](https://attack.mitre.org/techniques/T1059). Environment variables, aliases, characters, and other platform/language specific semantics can be used to evade signature based detections and application control mechanisms.(Citation: FireEye Obfuscation June 2017)(Citation: FireEye Revoke-Obfuscation July 2017)(Citation: PaloAlto EncodedCommand March 2017)
- Tactics
- Stealth
- Platforms
- ESXi, Linux, macOS, Network Devices, Windows
- MITRE Version
- 2.0
- Last Modified
- Sep 11, 2026
Sub-techniques (18)
T1027.001 · Binary PaddingT1027.002 · Software PackingT1027.003 · SteganographyT1027.004 · Compile After DeliveryT1027.005 · Indicator Removal from ToolsT1027.006 · HTML SmugglingT1027.007 · Dynamic API ResolutionT1027.008 · Stripped PayloadsT1027.009 · Embedded PayloadsT1027.010 · Command Obfuscation
Reported Context (713)
- The analyzed samples conceal script content using obfuscated strings and encoded, encrypted, and compressed data. MalwareINFO Pro Walkthrough Traces Obfuscated JSE and PowerShell Payloads
- The bundle uses string obfuscation and includes gzip-compressed, AES-256-GCM-encrypted embedded components. Malicious RubyGem strutil-core 1.0.1 Delivers Credential-Stealing Worm
- Malicious code in project files and source files is concealed behind long stretches of whitespace. Fake GitHub Security Tools Deliver Backdoors and Infostealers
- The article describes obfuscated Keitaro injection scripts and server-side cloaking that conceal the delivery chain. Infoblox Tracks Three Actors Reusing Expired Malicious Domains
- The modified CopyFail exploit passed its main logic as a string to exec() at runtime, which the article says made static analysis more difficult. CrowdStrike Finds Adversaries Weaponize Public Vulnerability Research Within Hours
CVE (158)
Malware (785)
People (265)
Threat Actors (404)
MITRE ATT&CK (446)
Vendors (358)
Products (1460)
Tools (692)
Industries (225)
Countries (120)
Note: Related entities, including threat actors, malware, CVEs, MITRE ATT&CK techniques, vendors, products, tools, countries, and industries, are shown when they appear in the same reporting. Their presence does not necessarily mean they were targeted, compromised, vulnerable, responsible for the activity, or directly involved in the incident.