test(llm-security): build poisoned fixtures at test time, never on disk

v8.1.0 AV surface, session S1. The three poisoned fixture trees
(signature-scan/poisoned, memory-scan/poisoned-project, trigger-scan/poisoned)
are deleted from disk and materialized into a temp dir by the new
tests/helpers/payload-trees.mjs. SIG-matching strings are assembled from
fragments, the zero-width carrier comes from String.fromCodePoint, and every
file carries the sha256 of the retired on-disk bytes;
tests/helpers/payload-trees.test.mjs asserts the materialized trees are
byte-identical (mutation-checked: one changed byte fails it).

Inline payload literals in signature-scanner, signature-scanner-custom-rules
and e2e/scan-pipeline are fragmented the same way; the literal U+200B in
attack-simulator, auto-cleaner-rce and auto-cleaner-traversal is replaced by
String.fromCodePoint(0x200B).

av-surface: a 3->0, a2 3->0, c 5->1, d 5->2, b 9->8 (webshell-b64 blob gone).
What remains (c=1, d=2, b) is under examples/** or is (b), both S2.
Suite 2261 / 2252 pass / 3 fail (av-surface b, c, d only) / 6 skip.
Golden output identical before/after (109/7/4, 61/61).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
This commit is contained in:
Kjell Tore Guttormsen 2026-09-22 13:07:38 +02:00
commit 31aa2b4943
Signed by: ktg
SSH key fingerprint: SHA256:JakMjO6FTBBzN0Bhfj9saOoEjaFxlSdYuZQQpM/lF9Q
21 changed files with 282 additions and 143 deletions

View file

@ -66,7 +66,7 @@ describe('signature-scanner: custom_rules_path (#36)', () => {
}],
}));
// A built-in webshell signature target
writeFileSync(join(dir, 'shell.php'), "<?php @eval($_POST['cmd']); ?>\n");
writeFileSync(join(dir, 'shell.php'), "<?php @ev" + "al($_POST['cmd']); ?>\n");
resetCounter();
const discovery = await discoverFiles(dir);
@ -86,7 +86,7 @@ describe('signature-scanner: custom_rules_path (#36)', () => {
const dir = mkdtempSync(join(tmpdir(), 'sig-custom-'));
try {
writePolicy(dir, { sig: { custom_rules_path: 'does-not-exist.json' } });
writeFileSync(join(dir, 'shell.php'), "<?php @eval($_POST['cmd']); ?>\n");
writeFileSync(join(dir, 'shell.php'), "<?php @ev" + "al($_POST['cmd']); ?>\n");
resetCounter();
const discovery = await discoverFiles(dir);
@ -141,7 +141,7 @@ describe('signature-scanner: custom_rules_path (#36)', () => {
try {
writePolicy(dir, { sig: { custom_rules_path: 'broken.json' } });
writeFileSync(join(dir, 'broken.json'), '{ not json');
writeFileSync(join(dir, 'shell.php'), "<?php @eval($_POST['cmd']); ?>\n");
writeFileSync(join(dir, 'shell.php'), "<?php @ev" + "al($_POST['cmd']); ?>\n");
resetCounter();
const discovery = await discoverFiles(dir);