Query: detection engineering for Dynamic API Resolution
Matching passage: T1027.007 Dynamic API Resolution. Tactics: stealth. Description: Adversaries may obfuscate then dynamically resolve API functions called by their malware in order to conceal malicious functionalities and impair defensive analysis. Malware commonly uses various [Native API](https://attack.mitre.org/techniques/T1106) functions provided by the OS to perform various tasks such as those involving processes, files, and other system artifacts. API functions called by malware may leave static artifacts such as strings in payload files. Defensive analysts may also uncover which functions a binary file may execute via an import address table (IAT) or other structures that help dynamically link calling code to the shared modules that provide functions.(Citation: Huntress API Hash)(Citation: IRED API Hashing) To avoid static or other defensive analysis, adversaries may use dynamic API resolution to conceal malware characteristics and functionalities. Similar to [Software Packing](https://attack.mitre.org/techniques/T1027/002), dynamic API resolution may change file signatures and obfuscate malicious API function calls until they are resolved and invoked during runtime. Various methods may be used to obfuscate malware calls to API functions. For example, hashes of function names are commonly stored in malware in lieu of literal strings. Malware can use these hashes (or other identifiers) to manually reproduce the linking and loading process using functions such as `GetProcAddress()` and `LoadLibrary()`. These hashes/identifiers can also be further obfuscated using encryption or other string manipulation tricks (requiring various forms of [Deobfuscate/Decode Files or Information](https://attack.mitre.org/techniques/T1140) during execution).(Citation: BlackHat API Packers)(Citation: Drakonia HInvoke)(Citation: Huntress API Hash)
Near-miss passage: T1027.017 SVG Smuggling. Tactics: stealth. Description: Adversaries may smuggle data and files past content filters by hiding malicious payloads inside of seemingly benign SVG files.(Citation: Trustwave SVG Smuggling 2025) SVGs, or Scalable Vector Graphics, are vector-based image files constructed using XML. As such, they can legitimately include `<script>` tags that enable adversaries to include malicious JavaScript payloads. However, SVGs may appear less suspicious to users than other types of executable files, as they are often treated as image files. SVG smuggling can take a number of forms. For example, threat actors may include content that: * Assembles malicious payloads(Citation: Talos SVG Smuggling 2022) * Downloads malicious payloads(Citation: Cofense SVG Smuggling 2024) * Redirects users to malicious websites(Citation: Bleeping Computer SVG Smuggling 2024) * Displays interactive content to users, such as fake login forms and download buttons.(Citation: Bleeping Computer SVG Smuggling 2024) SVG Smuggling may be used in conjunction with [HTML Smuggling](https://attack.mitre.org/techniques/T1027/006) where an SVG with a malicious payload is included inside an HTML file.(Citation: Talos SVG Smuggling 2022) SVGs may also be included in other types of documents, such as PDFs.