Query: what is T1027.011
Matching passage: T1027.011 Fileless Storage. Tactics: stealth. Description: Adversaries may store data in "fileless" formats to conceal malicious activity from defenses. Fileless storage can be broadly defined as any format other than a file. Common examples of non-volatile fileless storage in Windows systems include the Windows Registry, event logs, or WMI repository.(Citation: Microsoft Fileless)(Citation: SecureList Fileless) Shared memory directories on Linux systems (`/dev/shm`, `/run/shm`, `/var/run`, and `/var/lock`) and volatile directories on Network Devices (`/tmp` and `/volatile`) may also be considered fileless storage, as files written to these directories are mapped directly to RAM and not stored on the disk.(Citation: Elastic Binary Executed from Shared Memory Directory)(Citation: Akami Frog4Shell 2024)(Citation: Aquasec Muhstik Malware 2024)(Citation: Bitsight 7777 Botnet)(Citation: CISCO Nexus 900 Config). Similar to fileless in-memory behaviors such as [Reflective Code Loading](https://attack.mitre.org/techniques/T1620) and [Process Injection](https://attack.mitre.org/techniques/T1055), fileless data storage may remain undetected by antivirus and other endpoint security tools that can only access specific file formats from disk storage. Leveraging fileless storage may also allow adversaries to bypass the protections offered by read-only file systems in Linux.(Citation: Sysdig Fileless Malware 23022) Adversaries may use fileless storage to conceal various types of stored data, including payloads/shellcode (potentially being used as part of [Persistence](https://attack.mitre.org/tactics/TA0003)) and collected data not yet exfiltrated from the victim (e.g., [Local Data Staging](https://attack.mitre.org/techniques/T1074/001)). Adversaries also often encrypt, encode, splice, or otherwise obfuscate this fileless data when stored. Some forms of fileless storage activity may indirectly create artifacts in the file system, but in central and otherwise difficult to inspect formats such as the WMI (e.g., `%SystemRoot%\System32\Wbem\R
Near-miss passage: T1027.013 Encrypted/Encoded File. Tactics: stealth. Description: 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](https://attack.mitre.org/techniques/T1027/002), [Steganography](https://attack.mitre.org/techniques/T1027/003), and [Embedded Payloads](https://attack.mitre.org/techniques/T1027/009), 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](https://attack.mitre.org/techniques/T1140)) 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.(Citation: File obfuscation) 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](https://attack.mitre.org/techniques/T1566) 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](https://attack.mitre.org/techniques/T1204)).(Citation: SFX - Encrypted/Encoded File) 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](https://attack.mitre.org/techn