Scanning this repository with the SIG scanner produced 7 findings, 4 of them
on our own detection data: scanners/commons/CHANGELOG.md and
scanners/commons/signatures/malware-signatures.json. The ruleset that describes
xmrig and webshells is, byte for byte, a document containing those strings, so
the engine matched it as malware. EXCLUDED_PATH_RE already carried
knowledge/, tests/, docs/ and node_modules/ for exactly this reason; the
vendored commons arrived in v8 Phase 5 (bbada84) without being added.
One alternation branch closes it. Tests first: two cases added to
describe('signature-scanner: path exclusions'), both verified red against the
real scan() entry point before the regex changed.
Stated plainly, because it is a real cost and not a technicality: the branch is
`scanners\/commons` behind the existing `(^|\/)` prefix, so it matches that
two-segment path ANYWHERE in a target's relative path, not only at its root. A
webshell planted at vendor/scanners/commons/shell.php in a hostile repository is
therefore invisible to SIG. The second new test asserts that blind spot
deliberately, so it can never be discovered by accident. It is accepted because
anchoring at ^scanners/commons/ would miss the same payload one directory
deeper while re-opening the self-flag whenever the plugin is scanned from a
parent directory. TRG, AST, entropy and supply-chain still read these files;
only SIG identity-matching is blinded.
scanners/lib/supply-chain-data.mjs is NOT excluded. Its finding is a true
positive against real blocklist data.
Measured before: 7 findings. After: 3 (2 on STATE.md, 1 on
supply-chain-data.mjs). signature-scanner.test.mjs 23/23; custom-rules + e2e
54/54; golden-baseline 8/8 with suite-counts.json untouched.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SBJVYzwch63Rpk1hii1cNM
Fifth and last consumer swap of v8 Phase 5 step 4. The seven known-bad-identity
signatures stop living in knowledge/signatures.json and are built from the
vendored commons artifact signatures/malware-signatures.json instead.
Measured before the swap over all seven positions -- id, family, severity,
pattern, description, provenance, key order, and recompilation identity under
the engine's unconditional `i` flag: zero divergences over 56 checks, in order.
The commons copy was extracted from this repository's own file at b0de0ca and
had not drifted.
knowledge/signatures.json is REMOVED rather than left in place. Keeping it would
have left two files spelling one table with nothing gating the drift, and its
golden `file:` pin would have gone on passing while pinning bytes no scanner
reads -- a gate reporting success without running. The pin is replaced by a
walked-module anchor over SIGNATURE_RULES, which is strictly stronger: the pin
covered the bytes on disk, the walk covers what `new RegExp` made of them.
Golden diff was exactly that and nothing else: 7 ADDED, 1 REMOVED, 0 CHANGED
(102/7/5 -> 109/7/4), each added source verified equal to the recompiled commons
pattern.
compileRules() moves into the new lib module and is exported, so the built-in
ruleset and the operator's sig.custom_rules_path path keep one implementation
rather than two copies of the defaulting logic.
Coverage by construction, not by memory: the probe table in the scanner test is
asserted against the LOADED ruleset, so a rule commons adds cannot arrive
without an end-to-end probe. Mutation of the vendored JSON fires in three
directions -- under-match (xmrig alternative dropped) reddens two scanner tests
plus golden; over-match (webshell rule widened to a bare `shell`) reddens the
clean-fixture false-positive probe plus golden; reorder reddens the declared-
order test plus golden.
Loud failure is contract: an unresolvable commons writes one line to stderr
rather than silently disabling known-malware detection, and never throws.
Suite 2247 / 2241 pass / 6 skipped / 0 fail. suite-counts.json untouched.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0151x4FVg9Mn55C2LvHLpHKo
#21 the bash normalizer decoded only \xHH, leaving ANSI-C octal/\u/\U forms literal so canonical rm/curl never surfaced; now decodes all three. #23 file-discovery keyed on extname so .env.local/.env.example (extname .local/.example) were silently skipped; now matches multi-part suffixes. #42 a legitimate leading UTF-8 BOM was flagged HIGH (and the tool's own auto-cleaner refused to strip it); pos-0 BOM now excepted. #52 collapseLetterSpacing used a literal space, letting multi-space/tab spacing evade; now [ \t]+. #55 redact(_,60,0) did slice(-0) and leaked the whole unredacted URL; showEnd===0 now means no tail.
#30 embedded base64 (const x = "<base64>") never satisfied the whole-string decode, so the SIG identity engine never saw it; added decodeEmbeddedBase64 as an OPT-IN param on normalizeForScan (default off — appending a decoded copy would double-count per-match findings, e.g. content-extractor's injection scan) and enabled it only in signature-scanner, which dedups variants. #36 signature-scanner ignored the documented sig.custom_rules_path policy option; now loads+merges custom rules through the same family filter. Suite 2004/0.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TcQyMTQfyrsAapaCMPxTtQ
