A bootstrap chain is the ordered sequence a platform uses to start execution and load components. In web applications, this includes the earliest files, configuration hooks, and runtime helpers that run before the main app logic. Because each step can influence the next, anything inserted into the chain may execute very early.
In cyber security, bootstrap chains matter because attackers often target early-loading points to gain persistence or bypass later checks. A malicious drop-in, auto-prepend file, or altered startup configuration can reload malware before defenders notice it. For responders, tracing the bootstrap chain helps identify where code is first introduced, which component restores deleted payloads, and which hidden state must be removed to make cleanup complete.