diff --git a/.github/workflows/security-guard.yml b/.github/workflows/security-guard.yml
new file mode 100644
index 0000000..ecf5b6b
--- /dev/null
+++ b/.github/workflows/security-guard.yml
@@ -0,0 +1,28 @@
+name: Security Guard
+on:
+  pull_request:
+    types: [opened, synchronize, reopened]
+  schedule:
+    - cron: "17 3 * * *"
+  workflow_dispatch:
+permissions:
+  contents: read
+jobs:
+  npm:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22
+      - name: Verify npm projects
+        shell: bash
+        run: |
+          set -e
+          while IFS= read -r p; do
+            d="$(dirname "$p")"
+            npm install --ignore-scripts --no-audit --prefix "$d"
+            npm audit --audit-level=high --prefix "$d"
+            npm run build --if-present --prefix "$d"
+            npm test --if-present --prefix "$d"
+          done < <(find . -name package.json -not -path '*/node_modules/*' -not -path './.git/*' -print)