Microsoft GH-500 - GitHub Advanced Security Exam

Comprehensive and Detailed Explanation:

For code scanning to be triggered on a specific branch, the branch must contain the appropriate workflow file, typically located in the .github/workflows directory. This YAML file defines the code scanning configuration and specifies the events that trigger the scan (e.g., push, pull_request).​

Without the workflow file in the branch, GitHub Actions will not execute the code scanning process for that branch. The repository's visibility (private or public), the status of secret scanning, or the activity level of developers do not directly influence the triggering of code scanning.​

Validity checks, also called secret validation, allow GitHub to check if a detected secret is still active. If verified as live, the alert is marked as "valid", allowing security teams to prioritize the most critical leaks.

Push protection blocks secrets but does not check their validity. Custom patterns are user-defined and do not include live checks.

Code scanning is a static analysis feature that examines your source code to identify security vulnerabilities and coding errors. It runs either on every push, pull request, or a scheduled time depending on the workflow configuration.

It does not automatically contact maintainers, scan full Git history, or block pushes unless explicitly configured to do so.

When secret scanning is enabled on a private repository, GitHub performs a read-only analysis of the repository's contents. This includes the entire Git history and files to identify strings that match known secret patterns or custom-defined patterns.

GitHub does not alter the repository, and enabling secret scanning does not automatically enable code scanning or dependency review — each must be configured separately.

By default, users with Write, Maintain, or Admin permissions will receive notifications for new Dependabot alerts. However, Write permission is the minimum level needed to be automatically notified. Users with only Read access do not receive alerts unless added explicitly.

Comprehensive and Detailed Explanation:

Push protection for secret scanning custom patterns is an opt-in feature. This means that for each custom pattern defined in a repository, maintainers can choose to enable or disable push protection individually. This provides flexibility, allowing teams to enforce push protection on sensitive patterns while leaving it disabled for others.​

In a repository's Security tab, you can view:

Secret scanning alerts: Exposed credentials or tokens

Dependabot alerts: Vulnerable dependencies from the advisory database

Code scanning alerts: Vulnerabilities in code detected via static analysis (e.g., CodeQL)

You won’t see general "security status alerts" (not a formal category) or permission-related alerts here.

To exclude .txt and .md files from triggering workflows on pull requests to the main branch:

on: defines the event (e.g., pull_request)

pull_request: is the trigger

paths-ignore: is the key used to ignore file patterns

Example YAML:

yaml

CopyEdit

on:

pull_request:

branches:

- main

paths-ignore:

- '*.md'

- '*.txt'

Using paths: would include only specific files instead — not exclude. paths-ignore: is correct here.

The first step when you receive a secret scanning alert is to revoke the secret if it is still valid. This ensures the secret can no longer be used maliciously. Only after revoking it should you proceed to remove it from the code history and apply other mitigation steps.

Simply deleting the secret from the code does not remove the risk if it hasn’t been revoked — especially since it may already be exposed in commit history.

Dependabot alerts are generated as soon as GitHub detects a known vulnerability in one of your dependencies. GitHub does this by analyzing your repository’s dependency graph and matching it against vulnerabilities listed in the GitHub Advisory Database. Once a match is found, the system raises an alert automatically without waiting for a PR or manual action.

This allows organizations to proactively mitigate vulnerabilities as early as possible, based on real-time detection.