Live Active security incident? Get immediate response
MITRE ATT&CK® Technique

T1027.013: Encrypted/Encoded File

Adversaries may encrypt or encode files to obfuscate strings, bytes, and other specific patterns to impede detection. Encrypting and/or encoding file content aims to conceal malicious artifacts within a file used in an intrusion. Many other techniques, such as Software Packing, Steganography, and Embedded Payloads, share this same broad objective. Encrypting and/or encoding files could lead to a lapse in detection of static signatures, only for this malicious content to be revealed (i.e., Deobfuscate/Decode Files or Information) at the time of execution/use.

This type of file obfuscation can be applied to many file artifacts present on victim hosts, such as malware log/configuration and payload files.[1] Files can be encrypted with a hardcoded or user-supplied key, as well as otherwise obfuscated using standard encoding schemes such as Base64.

The entire content of a file may be obfuscated, or just specific functions or values (such as C2 addresses). Encryption and encoding may also be applied in redundant layers for additional protection.

For example, adversaries may abuse password-protected Word documents or self-extracting (SFX) archives as a method of encrypting/encoding a file such as a Phishing payload. These files typically function by attaching the intended archived content to a decompressor stub that is executed when the file is invoked (e.g., User Execution).[2]

Adversaries may also abuse file-specific as well as custom encoding schemes. For example, Byte Order Mark (BOM) headers in text files may be abused to manipulate and obfuscate file content until Command and Scripting Interpreter execution.

EnterpriseT1027.013Sub-techniqueObject v2.0 Modified
Glexia's Take

Analyst context for executives and security teams

Analyst confidence High

Encrypted or encoded files matter because they can make malicious content look harmless until it is decoded or used. For leaders, the risk is not the encoding itself; it is whether endpoint, email, file, and investigation workflows can still recognize suspicious behavior when static signatures miss hidden payloads, configuration values, or command-and-control details.

Executive priority

Prioritize this as a detection-resilience and incident-readiness issue across Linux, macOS, and Windows endpoints. Ask whether security teams can prove coverage beyond file signatures: behavioral prevention on endpoints, antimalware health, collection of file/process evidence, and response procedures for password-protected documents, self-extracting archives, Base64-like content, and files that decode at execution time. The ATT&CK relationships to multiple campaigns and groups make this a broadly relevant tradecraft pattern, but local exposure depends on your environment and telemetry.

Technical view

SOC and IR teams should validate detection around files whose contents are encrypted, encoded, layered, or revealed only during execution or use, especially where related behaviors include user execution, phishing payload delivery, command/scripting interpreter activity, and deobfuscation/decoding. Because MITRE provides no official detection text for this sub-technique, use the related DET0087 detection strategy and test whether endpoint behavior analytics, antimalware, and file inspection workflows can connect suspicious file creation or opening with follow-on process, script, archive, or decode activity.

Likely telemetry

  • Endpoint file creation, modification, quarantine, and scan results
  • Process execution lineage for documents, archives, self-extracting executables, scripts, and interpreters
  • Command-line and script content where collected
  • Antivirus/antimalware detections, prevention events, and update status
  • Endpoint behavior-prevention alerts involving suspicious file, process, or API activity

Detection direction

  • Do not rely only on static signatures; validate behavior-based detection for encoded or encrypted content that is decoded at runtime.
  • Tune analytics to connect suspicious files with follow-on execution, scripting, archive extraction, or deobfuscation activity rather than alerting on encoding alone.
  • Review blind spots for password-protected documents, self-extracting archives, custom encodings, and files with only selected values obfuscated, such as embedded addresses or configuration data.
  • Expect false positives from legitimate compressed, encrypted, or encoded files; require contextual signals such as source, user action, process lineage, and subsequent execution.
  • Use the relationship to Obfuscated Files or Information and Deobfuscate/Decode Files or Information as investigation pivots when reconstructing intrusion activity.

Mitigation priorities

  • Maintain antimalware across supported endpoints with current updates and central visibility into detections and failures.
  • Prioritize behavior prevention on endpoints so suspicious process, file, and API activity can be blocked or escalated even when content is hidden from signatures.
  • Harden handling of risky file types and delivery paths, especially documents, archives, and self-extracting files received through user-driven workflows.
  • Ensure IR playbooks include safe extraction, decoding, and analysis procedures for suspicious files without depending on the original visible content.
  • Use control validation exercises to confirm Linux, macOS, and Windows coverage rather than assuming one platform’s detection logic transfers to another.
Analyst notes and limits

This sub-technique is a stealth behavior under T1027, focused on concealing file content with encryption, encoding, or layered obfuscation. ATT&CK lists many campaign and group relationships, which supports broad relevance, but those relationships should guide threat-informed validation rather than imply current targeting of any specific organization.

MITRE does not provide official detection guidance for this object in the supplied fields. The available object describes behavior and related mitigations at a high level, so detection quality must be determined from local telemetry, endpoint tooling, file-handling controls, and incident response evidence.

Official MITRE ATT&CK definition

Encrypted/Encoded File

Adversaries may encrypt or encode files to obfuscate strings, bytes, and other specific patterns to impede detection. Encrypting and/or encoding file content aims to conceal malicious artifacts within a file used in an intrusion. Many other techniques, such as Software Packing, Steganography, and Embedded Payloads, share this same broad objective. Encrypting and/or encoding files could lead to a lapse in detection of static signatures, only for this malicious content to be revealed (i.e., Deobfuscate/Decode Files or Information) at the time of execution/use.

This type of file obfuscation can be applied to many file artifacts present on victim hosts, such as malware log/configuration and payload files.[1] Files can be encrypted with a hardcoded or user-supplied key, as well as otherwise obfuscated using standard encoding schemes such as Base64.

The entire content of a file may be obfuscated, or just specific functions or values (such as C2 addresses). Encryption and encoding may also be applied in redundant layers for additional protection.

For example, adversaries may abuse password-protected Word documents or self-extracting (SFX) archives as a method of encrypting/encoding a file such as a Phishing payload. These files typically function by attaching the intended archived content to a decompressor stub that is executed when the file is invoked (e.g., User Execution).[2]

Adversaries may also abuse file-specific as well as custom encoding schemes. For example, Byte Order Mark (BOM) headers in text files may be abused to manipulate and obfuscate file content until Command and Scripting Interpreter execution.

View the same entry on attack.mitre.org (MITRE-hosted reference; in-page links above use the Glexia ATT&CK library.)

Glexia analysis

How security teams should use this page

Treat this object as behavior context, not an attribution claim. Validate the related groups, software, data sources, and mitigations against official ATT&CK relationships and your own telemetry before making control-coverage decisions.

ATT&CK relationship table

Related techniques

This mirrors the MITRE pattern of making group, software, campaign, and technique relationships scannable. Relationship notes come from mirrored ATT&CK relationship text when available.

1 rows
Domain ID Name Relationship / procedure
Enterprise T1027 Obfuscated Files or Information This object subtechnique of Obfuscated Files or Information.
Associated objects

Groups, software, and campaigns

Group Enterprise

G0100: Inception

Inception is a cyber espionage group active since at least 2014. The group has targeted multiple industries and governmental entities primarily in Russia, but has also been active in the United States and throughout Europe, Asia, Africa, and the Middle East.[1][2][3]

Group Enterprise

G0066: Elderwood

Elderwood is a suspected Chinese cyber espionage group that was reportedly responsible for the 2009 Google intrusion known as Operation Aurora. [1] The group has targeted defense organizations, supply chain manufacturers, human rights and nongovernmental organizations (NGOs), and IT service providers. [2] [3]

Group Enterprise

G0012: Darkhotel

Darkhotel is a suspected South Korean threat group that has targeted victims primarily in East Asia since at least 2004. The group's name is based on cyber espionage operations conducted via hotel Internet networks against traveling executives and other select guests. Darkhotel has also conducted spearphishing campaigns and infected victims through peer-to-peer and file sharing networks.[1][2][3]

Group Enterprise

G0007: APT28

APT28 is a threat group that has been attributed to Russia's General Staff Main Intelligence Directorate (GRU) 85th Main Special Service Center (GTsSS) military unit 26165.[1][2] This group has been active since at least 2004.[3][4][5][6][7][8][9][10][11][12][13]

APT28 reportedly compromised the Hillary Clinton campaign, the Democratic National Committee, and the Democratic Congressional Campaign Committee in 2016 in an attempt to interfere with the U.S. presidential election.[5] In 2018, the US indicted five GRU Unit 26165 officers associated with APT28 for cyber operations (including close-access operations) conducted between 2014 and 2018 against the World Anti-Doping Agency (WADA), the US Anti-Doping Agency, a US nuclear facility, the Organization for the Prohibition of Chemical Weapons (OPCW), the Spiez Swiss Chemicals Laboratory, and other organizations.[14] Some of these were conducted with the assistance of GRU Unit 74455, which is also referred to as Sandworm Team.

Group Enterprise

G0026: APT18

APT18 is a threat group that has operated since at least 2009 and has targeted a range of industries, including technology, manufacturing, human rights groups, government, and medical. [1]

Group Enterprise

G0065: Leviathan

Leviathan is a Chinese state-sponsored cyber espionage group that has been attributed to the Ministry of State Security's (MSS) Hainan State Security Department and an affiliated front company.[1] Active since at least 2009, Leviathan has targeted the following sectors: academia, aerospace/aviation, biomedical, defense industrial base, government, healthcare, manufacturing, maritime, and transportation across the US, Canada, Australia, Europe, the Middle East, and Southeast Asia.[1][2][3][4]

Group Enterprise

G0121: Sidewinder

Sidewinder is a suspected Indian threat actor group that has been active since at least 2012. They have been observed targeting government, military, and business entities throughout Asia, primarily focusing on Pakistan, China, Nepal, and Afghanistan.[1][2][3]

Group Enterprise

G0087: APT39

APT39 is one of several names for cyber espionage activity conducted by the Iranian Ministry of Intelligence and Security (MOIS) through the front company Rana Intelligence Computing since at least 2014. APT39 has primarily targeted the travel, hospitality, academic, and telecommunications industries in Iran and across Asia, Africa, Europe, and North America to track individuals and entities considered to be a threat by the MOIS.[1][2][3][4][5]

Group Enterprise

G0032: Lazarus Group

Lazarus Group is a North Korean state-sponsored cyber threat group attributed to the Reconnaissance General Bureau (RGB). [1] [2] Lazarus Group has been active since at least 2009 and is reportedly responsible for the November 2014 destructive wiper attack on Sony Pictures Entertainment, identified by Novetta as part of Operation Blockbuster. Malware used by Lazarus Group correlates to other reported campaigns, including Operation Flame, Operation 1Mission, Operation Troy, DarkSeoul, and Ten Days of Rain.[3]

North Korea’s cyber operations have shown a consistent pattern of adaptation, forming and reorganizing units as national priorities shift. These units frequently share personnel, infrastructure, malware, and tradecraft, making it difficult to attribute specific operations with high confidence. Public reporting often uses “Lazarus Group” as an umbrella term for multiple North Korean cyber operators conducting espionage, destructive attacks, and financially motivated campaigns.[4][5][6]

Group Enterprise

G1031: Saint Bear

Saint Bear is a Russian-nexus threat actor active since early 2021, primarily targeting entities in Ukraine and Georgia. The group is notable for a specific remote access tool, Saint Bot, and information stealer, OutSteel in campaigns. Saint Bear typically relies on phishing or web staging of malicious documents and related file types for initial access, spoofing government or related entities.[1][2] Saint Bear has previously been confused with Ember Bear operations, but analysis of behaviors, tools, and targeting indicates these are distinct clusters.

Malware Enterprise

S1052: DEADEYE

DEADEYE is a malware launcher that has been used by APT41 since at least May 2021. DEADEYE has variants that can either embed a payload inside a compiled binary (DEADEYE.EMBED) or append it to the end of a file (DEADEYE.APPEND).[1]

Windows
Malware Enterprise

S1242: Qilin

Qilin is a ransomware family operated as a ransomware-as-a-service (RaaS) that has been active since at least 2022. It includes variants written in Go and Rust capable of targeting Windows, Linux, and VMware ESXi environments. Qilin shares functionality overlaps with Black Basta, REvil, and BlackCat ransomware. Qilin affiliates have targeted multiple entities worldwide with the majority of victims in the US, France, Canada, and the UK, primarily in the manufacturing, technology, financial services, and healthcare sectors.[1][2][3][4][5]

ESXiWindowsLinux
Malware Enterprise

S0678: Torisma

Torisma is a second stage implant designed for specialized monitoring that has been used by Lazarus Group. Torisma was discovered during an investigation into the 2020 Operation North Star campaign that targeted the defense sector.[1]

Windows
Malware Enterprise

S0136: USBStealer

USBStealer is malware that has been used by APT28 since at least 2005 to extract information from air-gapped networks. It does not have the capability to communicate over the Internet and has been used in conjunction with ADVSTORESHELL. [1] [2]

Windows
Malware Enterprise

S1153: Cuckoo Stealer

Cuckoo Stealer is a macOS malware with characteristics of spyware and an infostealer that has been in use since at least 2024. Cuckoo Stealer is a universal Mach-O binary that can run on Intel or ARM-based Macs and has been spread through trojanized versions of various potentially unwanted programs or PUP's such as converters, cleaners, and uninstallers.[1][2]

macOS
Malware Enterprise

S0487: Kessel

Kessel is an advanced version of OpenSSH which acts as a custom backdoor, mainly acting to steal credentials and function as a bot. Kessel has been active since its C2 domain began resolving in August 2018.[1]

Linux
Malware Enterprise

S0386: Ursnif

Ursnif is a banking trojan and variant of the Gozi malware observed being spread through various automated exploit kits, Spearphishing Attachments, and malicious links.[1][2] Ursnif is associated primarily with data theft, but variants also include components (backdoors, spyware, file injectors, etc.) capable of a wide variety of behaviors.[3]

Windows
Campaign Enterprise

C0045: ShadowRay

ShadowRay was a campaign that began in late 2023 targeting the education, cryptocurrency, biopharma, and other sectors through a vulnerability (CVE-2023-48022) in the Ray AI framework named ShadowRay. According to security researchers ShadowRay was the first known instance of AI workloads being activley exploited in the wild through vulnerabilities in AI infrastructure. CVE-2023-48022, which allows access to compute resources and sensitive data for exposed instances, remains unpatched and has been disputed by the vendor as they maintain that Ray is not intended for use outside of a strictly controlled network environment.[1]

Campaign Enterprise

C0002: Night Dragon

Night Dragon was a cyber espionage campaign that targeted oil, energy, and petrochemical companies, along with individuals and executives in Kazakhstan, Taiwan, Greece, and the United States. The unidentified threat actors searched for information related to oil and gas field production systems, financials, and collected data from SCADA systems. Based on the observed techniques, tools, and network activities, security researchers assessed the campaign involved a threat group based in China.[1]

Campaign Enterprise

C0006: Operation Honeybee

Operation Honeybee was a campaign that targeted humanitarian aid and inter-Korean affairs organizations from at least late 2017 through early 2018. Operation Honeybee initially targeted South Korea, but expanded to include Vietnam, Singapore, Japan, Indonesia, Argentina, and Canada. Security researchers assessed the threat actors were likely Korean speakers based on metadata used in both lure documents and executables, and named the campaign "Honeybee" after the author name discovered in malicious Word documents.[1]

Campaign Enterprise

C0063: 2025 Poland Wiper Attacks

2025 Poland Wiper Attacks is a Russian state-sponsored campaign that conducted destructive cyberattacks against Polish energy infrastructure in December 2025. Targets included more than 30 wind and photovoltaic farms, a combined heat and power (CHP) plant, and a manufacturing sector company. The attacks on the distributed energy resources (DER) disrupted communications between affected facilities and the distribution system operator, but did not impact electricity generation or heat supply. Across the campaign, threat actors deployed two previously undocumented wiper tools, DynoWiper, a Windows-based wiper and LazyWiper, a PowerShell wiper, distributed via malicious Group Policy Objects. At the CHP plant, threat actors had maintained access since at least March 2025, using that foothold to obtain credentials and move laterally before attempting wiper deployment. Some reporting has assessed the activity to be consistent with Russian Federal Security Service (FSB) threat activity group Dragonfly, also tracked as STATIC TUNDRA, while other reporting attributes the destructive wiper activities to the Russian General Staff Main Intelligence Directorate (GRU) threat activity group ELECTRUM, also tracked as Sandworm Team.[1][2][3][4]

Relationship explorer

All related ATT&CK context

Change history

Object version and sync metadata

The fields below describe the current mirrored snapshot. When Glexia retains multiple ATT&CK source imports, you can open the table to compare the same object across releases (hashes and MITRE timestamps). For MITRE’s own release notes and roadmap, see ATT&CK resources — Updates .

ATT&CK release
19.1
Object version
2.0
Created
Modified
Raw hash
5e60abc7c165f152...
Imported snapshots across ATT&CK releases (1)
Release Bundle imported Object version Modified Status Raw hash
19.1 2.0 Current bundle 5e60abc7c165…
Raw source

Mirrored ATT&CK source object

The raw object is retained through the mirrored ATT&CK source bundle and object hash. The raw endpoint returns the exact object from the mirrored bundle when available.

Source references

External references and citations

MITRE external references are preserved separately from Glexia analysis so citations remain traceable to their original source records.

  1. [1]
    File obfuscation

    Aspen Lindblom, Joseph Goodwin, and Chris Sheldon. (2021, July 19). Shlayer Malvertising Campaigns Still Using Flash Update Disguise. Retrieved March 29, 2024.

    Open source URL
  2. [2]
    SFX - Encrypted/Encoded File

    Jai Minton. (2023, March 31). How Falcon OverWatch Investigates Malicious Self-Extracting Archives, Decoy Files and Their Hidden Payloads. Retrieved March 29, 2024.

    Open source URL
  3. [3]
    mitre-attack T1027.013
    Open source URL
Source and licensing

Source: MITRE ATT&CK®. © 2026 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation. MITRE ATT&CK and ATT&CK are registered trademarks of The MITRE Corporation. Glexia is not affiliated with or endorsed by MITRE.