stripInjection is the remote-scan indirection layer: its `sanitized`
output is what an LLM agent actually reads, verbatim, via
sanitized_content in the evidence package. It scanned two variants of
each file — the raw text and normalizeForScan(text) — but removed
matches with `sanitized.replace(match[0], ...)` against the RAW text
only.
For a match found in the decoded variant, match[0] IS the decoded
string, which by construction does not occur in the raw text. The
replace was therefore a silent no-op: the finding was reported while the
encoded payload was passed to the agent untouched. Every obfuscation the
normalizer exists to defeat — HTML entities, URL encoding, \u escapes,
hex, base64, letter-spacing, Unicode tags — reached the agent intact.
The worst case is the intended one: detection said "critical injection
found" and shipped the injection along with the verdict.
- Pass 1 redacts the whole source LINE whose own normalized form carries
the pattern. Line granularity is deliberate: decoding is not
length-preserving, so decoded match offsets cannot be mapped back onto
the original text.
- Pass 2 keeps the existing literal replacement and finding collection.
- Residual gap, made explicit rather than silent: a payload encoded
across MULTIPLE lines matches whole-text normalization but no single
line, so it cannot be attributed. Those findings now carry
`unstripped: true`. Whole-file redaction was considered and rejected —
normalizeForScan base64-decodes any long blob, so a benign asset could
blank an entire file's evidence.
- stripInjection exported via __testing, and main() is now behind the
standard isMain guard (copied from dashboard-aggregator.mjs) so
importing the module does not execute the CLI. CLI verified unchanged
against the evil-project-health fixture: 7 files, 6 injection
findings, risk_level critical.
This boundary had no direct test coverage before this commit.
npm test: 1890/1890 green (1884 + 6 new).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TcQyMTQfyrsAapaCMPxTtQ
Kjell Tore Guttormsen
4f21374e8c