owasp-dep-scan/blint/loldrivers-rules

LOLDrivers rule coverage loop

Re-measures blint's driver rules against the LOLDrivers corpus of known-vulnerable drivers, then drafts rules for measured gaps. The corpus publishes each sample's imported function list, so import-based rules can be evaluated at scale without downloading any binaries.

This skill never commits and never edits shipped rule files directly. It produces a coverage report plus candidate rules in a staging file for a human to review. A high hit count proves a gap exists, not that a proposed rule is sound.

1. Measure

python contrib/loldrivers/sync_loldrivers.py --report /tmp/blint-loldrivers/coverage.json

Add --dataset <file> to reuse a local copy instead of refetching, and --update-snapshot once you have finished a pass so the next run reports only what is new.

Read from the report:

• rule_hits — per-rule hit counts. A rule that drops sharply between runs

usually means a regression in the rule, not a change in the corpus.

• undetected_count / undetected_percent — samples where no driver rule fires.
• candidate_imports — imports ranked by frequency among undetected samples.

This is the raw material for new rules.

2. Decide whether there is a real gap

Group candidate_imports into capability clusters by hand before proposing anything. A cluster is rule-worthy when the imports co-occur and together grant a single coherent primitive. For example ZwOpenProcess + PsLookupProcessByProcessId

• KeStackAttachProcess + ObOpenObjectByPointer is a cross-process

memory/handle primitive; that is one rule, not four.

Reject a cluster when:

• The imports are ubiquitous plumbing (locks, string helpers, pool allocation).

Extend UNINTERESTING_IMPORTS in the sync script instead.

• An existing rule already covers the capability under a different name. Check

blint/data/annotations/review_imports_pe.yml and review_drivers_win.yml first — overlapping rules inflate apparent coverage without adding signal.

• The capability is normal for the driver class in question. Filesystem and

network filter drivers legitimately import alarming-looking APIs.

3. Draft the rule

Delegate drafting of each accepted cluster to a subagent, one agent per cluster, so the drafts stay independent. Give the agent: the cluster's imports, their undetected-sample counts, and the instruction to match the existing rule style in blint/data/annotations/review_drivers_win.yml.

Every rule needs an id, title, summary, description and check_type. Requirements for the description, which is what a reviewer actually reads:

• State the primitive the imports grant and why it matters in kernel context.
• Name a concrete driver or CVE that exhibits it, when the corpus entry has one

(Category, Tags and the loldrivers Resources field are the sources).

• State the legitimate uses that will cause false positives. Every rule in this

area fires on benign vendor drivers; say so rather than implying certainty.

Write drafts to contrib/loldrivers/candidate-rules.yml, never to the shipped annotation files.

Prefer an IMPORT_REVIEWS rule when a set of import names is sufficient. Use a BINARY_REVIEWS rule with check_type: binary_analysis when the signal depends on a combination or on the absence of something, since import pattern rules cannot express either; that needs a matching branch in _evaluate_binary_analysis in blint/lib/binary_reviews.py.

4. Verify before proposing

A draft is not a candidate until all of these hold:

# Rules parse and load into the expected group
python -c "import yaml; list(yaml.safe_load_all(open('contrib/loldrivers/candidate-rules.yml')))"
# Nothing already shipped regressed
python -m pytest tests/test_driver_ioctl.py tests/test_analysis.py -q
# Coverage actually improved, and by how much
python contrib/loldrivers/sync_loldrivers.py --dataset <local copy> --report /tmp/after.json

Load the candidate file with --custom-rules-dir (or copy it into a scratch annotations directory) when re-measuring, and report the before/after undetected_percent. A candidate rule that does not move that number is not worth shipping.

Then report to the user: the coverage delta, each proposed rule with its cluster evidence, and the false-positive exposure you could not rule out. Note explicitly that the corpus contains only known-vulnerable drivers, so it measures recall only — it says nothing about how often a rule fires on benign drivers. Claims about precision need a separate corpus of legitimate signed drivers.

Scheduling

To run this periodically:

/loop 168h /loldrivers-rules

Weekly matches the corpus's rate of change; daily mostly re-reports the same gaps. Use --update-snapshot at the end of a pass so subsequent runs surface newly published drivers rather than the whole corpus.