Query: detection engineering for Embedded Payloads
Matching passage: T1027.009 Embedded Payloads. Tactics: stealth. Description: Adversaries may embed payloads within other files to conceal malicious content from defenses. Otherwise seemingly benign files (such as scripts and executables) may be abused to carry and obfuscate malicious payloads and content. In some cases, embedded payloads may also enable adversaries to [Subvert Trust Controls](https://attack.mitre.org/techniques/T1553) by not impacting execution controls such as digital signatures and notarization tickets.(Citation: Sentinel Labs) Adversaries may embed payloads in various file formats to hide payloads.(Citation: Microsoft Learn) This is similar to [Steganography](https://attack.mitre.org/techniques/T1027/003), though does not involve weaving malicious content into specific bytes and patterns related to legitimate digital media formats.(Citation: GitHub PSImage) For example, adversaries have been observed embedding payloads within or as an overlay of an otherwise benign binary.(Citation: Securelist Dtrack2) Adversaries have also been observed nesting payloads (such as executables and run-only scripts) inside a file of the same format.(Citation: SentinelLabs reversing run-only applescripts 2021) Embedded content may also be used as [Process Injection](https://attack.mitre.org/techniques/T1055) payloads used to infect benign system processes.(Citation: Trend Micro) These embedded then injected payloads may be used as part of the modules of malware designed to provide specific features such as encrypting C2 communications in support of an orchestrator module. For example, an embedded module may be injected into default browsers, allowing adversaries to then communicate via the network.(Citation: Malware Analysis Report ComRAT)
Near-miss passage: T1027.018 Invisible Unicode. Tactics: stealth. Description: Adversaries may abuse invisible or non-printing Unicode characters to conceal malicious content within files, scripts, or text. By inserting characters that do not visibly render, adversaries may hide data, alter how content is interpreted, or make malicious code appear as benign text or whitespace. Adversaries may encode these malicious payloads, using binary, Base64, or custom schemes, to be reconstructed at runtime through scripting features such as [JavaScript](https://attack.mitre.org/techniques/T1059/007) Proxy traps, `eval()`, or other dynamic execution methods. This technique enables adversaries to evade visual inspection and basic static analysis by hiding malicious encoded content in innocuous text.(Citation: PUAs Unicode - Eriksen)(Citation: Tycoon2FA - Unicode)(Citation: Unicode - Veracode) Unicode is a standardized character encoding model that assigns a unique numerical value, known as a code point, to every character across writing systems, enabling consistent text representation across platforms, applications, and languages. Code points are represented as `U+` followed by a hexadecimal value and may be encoded using formats such as `UTF-8` or `UTF-16`. Adversaries may abuse the valid code points in Unicode that are not visibly rendered but still take up bytes, such as zero-width spaces, variation selectors, or bidirectional formatting controls, to conceal malicious payloads.(Citation: Tycoon2FA - Unicode)(Citation: GlassWorm - Unicode)(Citation: Unicode and Hidden Prompts - Perets) Adversaries may additionally exploit Private Use Area (PUA) characters, a range of code points reserved for custom assignment. PUA characters that are not defined by a font or application are typically rendered blank.(Citation: PUAs Unicode - Eriksen) Unicode characters may also be leveraged in support of other techniques such as [Phishing](https://attack.mitre.org/techniques/T1660), [Right-to-Left Override](https://attack.mitre.org/techniques/T1036/002), or [User Executio