diff --git a/extensions/qa-matrix/src/runners/contract/scenario-runtime-cli.test.ts b/extensions/qa-matrix/src/runners/contract/scenario-runtime-cli.test.ts
index bfabd142ef0a..884b2432aaae 100644
--- a/extensions/qa-matrix/src/runners/contract/scenario-runtime-cli.test.ts
+++ b/extensions/qa-matrix/src/runners/contract/scenario-runtime-cli.test.ts
@@ -77,11 +77,12 @@ describe("Matrix QA CLI runtime", () => {
 
       testing.killMatrixQaCliChild(child, "SIGTERM", runTaskkill);
 
-      expect(runTaskkill).toHaveBeenNthCalledWith(1, "taskkill", ["/PID", "12345", "/T"], {
+      const taskkillPath = path.win32.join("C:\\Windows", "System32", "taskkill.exe");
+      expect(runTaskkill).toHaveBeenNthCalledWith(1, taskkillPath, ["/PID", "12345", "/T"], {
         stdio: "ignore",
         windowsHide: true,
       });
-      expect(runTaskkill).toHaveBeenNthCalledWith(2, "taskkill", ["/PID", "12345", "/T", "/F"], {
+      expect(runTaskkill).toHaveBeenNthCalledWith(2, taskkillPath, ["/PID", "12345", "/T", "/F"], {
         stdio: "ignore",
         windowsHide: true,
       });
diff --git a/extensions/qa-matrix/src/runners/contract/scenario-runtime-cli.ts b/extensions/qa-matrix/src/runners/contract/scenario-runtime-cli.ts
index 9412d5661bab..278d2853d59f 100644
--- a/extensions/qa-matrix/src/runners/contract/scenario-runtime-cli.ts
+++ b/extensions/qa-matrix/src/runners/contract/scenario-runtime-cli.ts
@@ -8,6 +8,7 @@ import { setTimeout as sleep } from "node:timers/promises";
 import { formatErrorMessage } from "openclaw/plugin-sdk/error-runtime";
 import { redactSensitiveText } from "openclaw/plugin-sdk/logging-core";
 import { resolvePreferredOpenClawTmpDir } from "openclaw/plugin-sdk/temp-path";
+import { resolveMatrixQaWindowsSystem32ExePath } from "../../windows-system-tools.js";
 
 export type MatrixQaCliRunResult = {
   args: string[];
@@ -111,16 +112,17 @@ function killMatrixQaCliChild(
 ): void {
   if (process.platform === "win32") {
     if (child.pid) {
+      const taskkillPath = resolveMatrixQaWindowsSystem32ExePath("taskkill.exe");
       const args = ["/PID", String(child.pid), "/T"];
       if (signal === "SIGKILL") {
         args.push("/F");
       }
-      const result = runTaskkill("taskkill", args, { stdio: "ignore", windowsHide: true });
+      const result = runTaskkill(taskkillPath, args, { stdio: "ignore", windowsHide: true });
       if (!result.error && result.status === 0) {
         return;
       }
       if (signal !== "SIGKILL") {
-        const forceResult = runTaskkill("taskkill", [...args, "/F"], {
+        const forceResult = runTaskkill(taskkillPath, [...args, "/F"], {
           stdio: "ignore",
           windowsHide: true,
         });
diff --git a/extensions/qa-matrix/src/windows-system-tools.test.ts b/extensions/qa-matrix/src/windows-system-tools.test.ts
new file mode 100644
index 000000000000..3bd857bd6b7b
--- /dev/null
+++ b/extensions/qa-matrix/src/windows-system-tools.test.ts
@@ -0,0 +1,32 @@
+// Qa Matrix tests cover Windows system tool path resolution.
+import { describe, expect, it } from "vitest";
+import {
+  resolveMatrixQaWindowsSystem32ExePath,
+  resolveMatrixQaWindowsSystemRoot,
+} from "./windows-system-tools.js";
+
+describe("qa-matrix windows system tools", () => {
+  it("resolves System32 executables from a trusted SystemRoot", () => {
+    expect(resolveMatrixQaWindowsSystemRoot({ SystemRoot: "D:\\Windows\\" })).toBe("D:\\Windows");
+    expect(
+      resolveMatrixQaWindowsSystem32ExePath("taskkill.exe", { SystemRoot: "D:\\Windows\\" }),
+    ).toBe("D:\\Windows\\System32\\taskkill.exe");
+  });
+
+  it("falls back to the default Windows root when env roots are unsafe", () => {
+    expect(
+      resolveMatrixQaWindowsSystem32ExePath("taskkill.exe", {
+        WINDIR: "\\\\attacker\\share",
+      }),
+    ).toBe("C:\\Windows\\System32\\taskkill.exe");
+  });
+
+  it("rejects non-basename System32 executable names", () => {
+    expect(() => resolveMatrixQaWindowsSystem32ExePath("..\\taskkill.exe")).toThrow(
+      "Invalid Windows System32 executable name",
+    );
+    expect(() => resolveMatrixQaWindowsSystem32ExePath("taskkill")).toThrow(
+      "Invalid Windows System32 executable name",
+    );
+  });
+});
diff --git a/extensions/qa-matrix/src/windows-system-tools.ts b/extensions/qa-matrix/src/windows-system-tools.ts
new file mode 100644
index 000000000000..325f7872a2e1
--- /dev/null
+++ b/extensions/qa-matrix/src/windows-system-tools.ts
@@ -0,0 +1,62 @@
+// Qa Matrix resolves Windows system tools without trusting PATH.
+import path from "node:path";
+
+const DEFAULT_WINDOWS_SYSTEM_ROOT = "C:\\Windows";
+
+function getEnvValueCaseInsensitive(
+  env: Record<string, string | undefined>,
+  expectedKey: string,
+): string | undefined {
+  const direct = env[expectedKey];
+  if (direct !== undefined) {
+    return direct;
+  }
+  const expected = expectedKey.toUpperCase();
+  const actualKey = Object.keys(env).find((key) => key.toUpperCase() === expected);
+  return actualKey ? env[actualKey] : undefined;
+}
+
+function normalizeWindowsSystemRoot(raw: string | undefined): string | null {
+  const trimmed = raw?.trim();
+  if (
+    !trimmed ||
+    trimmed.includes("\0") ||
+    trimmed.includes("\r") ||
+    trimmed.includes("\n") ||
+    trimmed.includes(";")
+  ) {
+    return null;
+  }
+  const normalized = path.win32.normalize(trimmed);
+  if (!path.win32.isAbsolute(normalized) || normalized.startsWith("\\\\")) {
+    return null;
+  }
+  const parsed = path.win32.parse(normalized);
+  if (!/^[A-Za-z]:\\$/u.test(parsed.root) || normalized.length <= parsed.root.length) {
+    return null;
+  }
+  return normalized.replace(/[\\/]+$/u, "");
+}
+
+export function resolveMatrixQaWindowsSystemRoot(
+  env: Record<string, string | undefined> = process.env,
+): string {
+  return (
+    normalizeWindowsSystemRoot(getEnvValueCaseInsensitive(env, "SystemRoot")) ??
+    normalizeWindowsSystemRoot(getEnvValueCaseInsensitive(env, "WINDIR")) ??
+    DEFAULT_WINDOWS_SYSTEM_ROOT
+  );
+}
+
+export function resolveMatrixQaWindowsSystem32ExePath(
+  executableName: string,
+  env: Record<string, string | undefined> = process.env,
+): string {
+  if (
+    path.win32.basename(executableName) !== executableName ||
+    !/^[A-Za-z0-9_.-]+\.exe$/u.test(executableName)
+  ) {
+    throw new Error(`Invalid Windows System32 executable name: ${executableName}`);
+  }
+  return path.win32.join(resolveMatrixQaWindowsSystemRoot(env), "System32", executableName);
+}