T1027 Obfuscated Files or Information

Technique

T1027

Tactics

Defense Evasion

Research, 90 days

12

KEV CVEs mapped

5

SigmaHQ rules

94

Elastic, Splunk

59

thrunt rules

0

Upstream

https://attack.mitre.org/techniques/T1027

MITRE 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)

KEV CVEs mapped to this technique

MITRE CTID maps these KEV CVEs to this technique by hand. They are the actively exploited vulnerabilities behind this technique's KEV signal.

• CVE-2022-24086
• CVE-2021-44077
• CVE-2021-40539
• CVE-2021-40449
• CVE-2010-2883

Research citing this technique

Reports and advisories from the last 90 days that cite this technique.

• 2026-11-03 Flare: Inside a Microsoft Lookalike Domain Masquerading as Czech Company’s IT Department Infrastructure
• 2026-10-30 Darktrace: CikaBika Bot: Inside a Discord RAT Campaign
• 2026-10-29 Cisco Talos: IR trends Q3 2026: Actors impersonate IT help desks in vishing attacks as ransomware activity increases
• 2026-10-22 Group-IB: Inside SiriusQT: A Seriously Skilled RAT
• 2026-10-19 Rapid7: Rapid7 Analysis: NetScaler intrusions chaining CVE-2026-88771 and CVE-2026-88779
• 2026-10-14 Group-IB: KGB RAT: A Fully Undetectable Windows Trojan Built to Spy, Steal, and Terrorize
• 2026-10-06 Flare: CrocoRat Adds a New Twist to ClickFix with DNS Payload Delivery
• 2026-09-25 Google Threat Intelligence: ShinyHunters Renewed Mass Exploitation Campaign Targeting Oracle PeopleSoft
• 2026-09-14 Group-IB: Smish. Click. Drained: Inside the Smishing Triad’s Phishing Cockpit
• 2026-09-03 Group-IB: The Outsider Phishing Kit: A Resilient Threat in the Face of Law Enforcement Action

Showing the 10 most recent of 12.

Detection coverage

SigmaHQ community rules

• Turla Group Commands May 2020 (emerging-threats)
• Potential Emotet Activity (emerging-threats)
• Operation Wocao Activity (emerging-threats)
• Operation Wocao Activity - Security (emerging-threats)
• Potentially Suspicious Long Filename Pattern - Linux (threat-hunting)
• Potential CommandLine Obfuscation Using Unicode Characters (threat-hunting)
• Potential Suspicious Execution From GUID Like Folder Names (threat-hunting)
• Suspicious Filename with Embedded Base64 Commands (core)
• Decode Base64 Encoded Text (core)
• Decode Base64 Encoded Text -MacOs (core)
• Invoke-Obfuscation CLIP+ Launcher - Security (core)
• Invoke-Obfuscation Obfuscated IEX Invocation - Security (core)
• Invoke-Obfuscation STDIN+ Launcher - Security (core)
• Invoke-Obfuscation VAR+ Launcher - Security (core)
• Invoke-Obfuscation COMPRESS OBFUSCATION - Security (core)
• Invoke-Obfuscation RUNDLL LAUNCHER - Security (core)
• Invoke-Obfuscation Via Stdin - Security (core)
• Invoke-Obfuscation Via Use Clip - Security (core)
• Invoke-Obfuscation Via Use MSHTA - Security (core)
• Invoke-Obfuscation Via Use Rundll32 - Security (core)
• Invoke-Obfuscation VAR++ LAUNCHER OBFUSCATION - Security (core)
• Password Protected ZIP File Opened (Suspicious Filenames) (core)
• Password Protected ZIP File Opened (Email Attachment) (core)
• Password Protected ZIP File Opened (core)
• Invoke-Obfuscation CLIP+ Launcher - System (core)

Showing 25 of 94 community rules. the full set is tagged attack.t1027 in SigmaHQ.

Elastic and Splunk rules

• Data Encrypted via OpenSSL Utility (elastic)
• ROT Encoded Python Script Execution (elastic)
• GenAI Process Compiling or Generating Executables (elastic)
• GenAI Process Performing Encoding/Chunking Prior to Network Activity (elastic)
• Long Base64 Encoded Command via Scripting Interpreter (elastic)
• Command Line Obfuscation via Whitespace Padding (elastic)
• Decoded Payload Piped to Interpreter Detected via Defend for Containers (elastic)
• Encoded Payload Detected via Defend for Containers (elastic)
• High Command Line Entropy Detected for Privileged Commands (elastic)
• GenAI Prompt Contains Base64-Encoded Payload (elastic)
• ESXi Shell Command Obfuscation (elastic)
• Base16 or Base32 Encoding/Decoding Activity (elastic)
• Unusual Base64 Encoding/Decoding Activity (elastic)
• Potential Hex Payload Execution via Command-Line (elastic)
• Potential Hex Payload Execution via Common Utility (elastic)
• Base64 Decoded Payload Piped to Interpreter (elastic)
• Multi-Base64 Decoding Attempt from Suspicious Location (elastic)
• Suspicious Content Extracted or Decompressed via Funzip (elastic)
• Suspicious Powershell Script (elastic)
• Potential Antimalware Scan Interface Bypass via PowerShell (elastic)
• Suspicious .NET Code Compilation (elastic)
• Microsoft Build Engine Started an Unusual Process (elastic)
• Command Obfuscation via Unicode Modifier Letters (elastic)
• PowerShell Suspicious Payload Encoded and Compressed (elastic)
• PowerShell Script with Encryption/Decryption Capabilities (elastic)

Showing 25 of 59.

Signal counts reflect the current corpus snapshot. Research citations are the technique IDs named in vendor reports and government advisories from the last 90 days; KEV mappings come from MITRE CTID. Coverage is the SigmaHQ rule inventory (core, emerging-threats, threat-hunting) at release r2026-07-01 plus Elastic and Splunk production rules. Rule bodies are not mirrored; links go upstream.