Query: what is T1677
Matching passage: T1677 Poisoned Pipeline Execution. Tactics: execution. Description: Adversaries may manipulate continuous integration / continuous development (CI/CD) processes by injecting malicious code into the build process. There are several mechanisms for poisoning pipelines: * In a <b>Direct Pipeline Execution</b> scenario, the threat actor directly modifies the CI configuration file (e.g., `gitlab-ci.yml` in GitLab). They may include a command to exfiltrate credentials leveraged in the build process to a remote server, or to export them as a workflow artifact.(Citation: Unit 42 Palo Alto GitHub Actions Supply Chain Attack 2025)(Citation: OWASP CICD-SEC-4) * In an <b>Indirect Pipeline Execution</b> scenario, the threat actor injects malicious code into files referenced by the CI configuration file. These may include makefiles, scripts, unit tests, and linters.(Citation: OWASP CICD-SEC-4) * In a <b>Public Pipeline Execution</b> scenario, the threat actor does not have direct access to the repository but instead creates a malicious pull request from a fork that triggers a part of the CI/CD pipeline. For example, in GitHub Actions, the `pull_request_target` trigger allows workflows running from forked repositories to access secrets. If this trigger is combined with an explicit pull request checkout and a location for a threat actor to insert malicious code (e.g., an `npm build` command), a threat actor may be able to leak pipeline credentials.(Citation: Unit 42 Palo Alto GitHub Actions Supply Chain Attack 2025)(Citation: GitHub Security Lab GitHub Actions Security 2021) Similarly, threat actors may craft pull requests with malicious inputs (such as branch names) if the build pipeline treats those inputs as trusted.(Citation: Wiz Ultralytics AI Library Hijack 2024)(Citation: Synactiv Hijacking GitHub Runners)(Citation: GitHub Security Labs GitHub Actions Security Part 2 2021) Finally, if a pipeline leverages a self-hosted runner, a threat actor may be able to execute arbitrary code on a host inside the organization’s network.(Citation: John Staw
Near-miss passage: T1127 Trusted Developer Utilities Proxy Execution. Tactics: stealth, execution. Description: Adversaries may take advantage of trusted developer utilities to proxy execution of malicious payloads. There are many utilities used for software development related tasks that can be used to execute code in various forms to assist in development, debugging, and reverse engineering.(Citation: engima0x3 DNX Bypass)(Citation: engima0x3 RCSI Bypass)(Citation: Exploit Monday WinDbg)(Citation: LOLBAS Tracker) These utilities may often be signed with legitimate certificates that allow them to execute on a system and proxy execution of malicious code through a trusted process that effectively bypasses application control solutions. Smart App Control is a feature of Windows that blocks applications it considers potentially malicious from running by verifying unsigned applications against a known safe list from a Microsoft cloud service before executing them.(Citation: Microsoft Smart App Control) However, adversaries may leverage "reputation hijacking" to abuse an operating system’s trust of safe, signed applications that support the execution of arbitrary code. By leveraging [Trusted Developer Utilities Proxy Execution](https://attack.mitre.org/techniques/T1127) to run their malicious code, adversaries may bypass Smart App Control protections.(Citation: Elastic Security Labs)