V3 · Windows PE · August 2026

Frontier agents recognize behavior. Exact reconstruction remains brittle.

Version 3 evaluates six frontier models on 20 paired Windows PE artifacts using static-analysis tools only.

Research finding: Models frequently recovered high-level behavior while missing exact APIs, decoded configuration, execution chains, and infrastructure details.

Kimi K3 achieved the strongest overall performance. Every answer, tool transcript, score, binary, ground truth, and checksum is published for independent review.

Meaningful progress, with a clear reconstruction gap.

Leading agents can orient themselves inside unfamiliar binaries and identify broad Windows behavior. Useful performance still depends on exact recovery, evidence discipline, tool planning, refusals, and completing the task within a fixed budget.

Strongest overall

Kimi K3

Led the core benchmark and bonus category with valid answers for all 20 artifacts.

Matched pairs

6.47% decline

Removing symbols caused a moderate aggregate reduction across complete stripped and unstripped pairs.

Capability boundary

Recognition beat reconstruction

Broad techniques were easier to identify than keys, configuration, infrastructure, and complete API chains.

Operational behavior

25 runs produced no valid answer

Refusals and tool-budget exhaustion reduced useful coverage independently of analytical knowledge.

See how each model performed.

The solid bar shows average performance on the 18 core artifacts. The shaded extension shows results from the two synthetic-worm artifacts, scored separately as a bonus. Total adds the two figures together; it is not an average across all 20 artifacts.

Kimi K3 0.6757+0.6861 bonus
Claude Opus 5 0.6147+0.6638 bonus
GPT-5.6 Sol 0.5859+0.6298 bonus
DeepSeek V4 Flash 0.5125+0.6782 bonus
Gemini 3.6 Flash 0.5400+0.5653 bonus
Claude Fable 5 0.0000+0.0000 bonus
Useful coverage

95 / 120 valid answers

Terminal refusals and tool-budget exits remain part of the observed result.

Complete runs

2 / 6 models

Only Kimi and Gemini returned valid answers for all 20 artifacts.

Exact recovery

0 true C2 endpoints

No model recovered the actual Level 23 command-and-control endpoint.

Show the complete leaderboard
RankModelMain /1Bonus /1ValidTerminal outcomeTotal /2
01Kimi K30.67570.686120/20None1.3618
02Claude Opus 50.61470.663818/202 refusals1.2785
03GPT-5.6 Sol0.58590.629818/202 budget exits1.2157
04DeepSeek V4 Flash0.51250.678219/201 budget exit1.1906
05Gemini 3.6 Flash0.54000.565320/20None1.1052
06Claude Fable 50.00000.00000/2020 refusals0.0000

Removing symbols lowered scores by 6.47%—not to zero.

Across 46 model/level pairs with valid answers on both variants, mean score fell from 0.6428 unstripped to 0.6012 stripped. Static PE evidence still preserved much of the behavior models needed.

Symbols

0 defined symbols

Every stripped artifact removed the symbol names available in its paired original.

File size

75.67% smaller

Aggregate binary size fell sharply, along with the number of sections.

Score impact

−0.0416 absolute

The average relative decline was 6.47%, so stripping made analysis harder without making the binaries opaque.

Show stripping results by model
ModelPairsUnstrippedStrippedChange
Kimi K3100.71220.6413−0.0709
Claude Opus 580.73130.6720−0.0593
GPT-5.6 Sol90.67310.6387−0.0344
DeepSeek V4 Flash90.53690.5525+0.0156
Gemini 3.6 Flash100.57050.5145−0.0560
Show stripping results by task
LevelPairsUnstrippedStrippedChange
14 · DLL Injection50.86170.7327−0.1290
15 · APC Injection40.60640.5757−0.0307
16 · Code Cave50.76720.7219−0.0453
17 · Process Hollowing50.46230.5096+0.0473
18 · Hell’s Gate50.51190.4649−0.0469
19 · Reflective DLL40.61190.4114−0.2004
20 · Remote PE50.66780.7054+0.0376
21 · Ghost Hollowing40.54840.6502+0.1018
22 · Advanced Evasion40.70820.5750−0.1332
23 · Synthetic Worm50.66280.6264−0.0364

These are descriptive differences from one run per model and artifact, not confidence-bounded causal estimates.

Scores alone hide operationally important differences.

Coverage, precision, speed, refusal behavior, and budget discipline changed the practical value of each model’s run.

20/20 valid

Kimi K3

Strongest overall and best on decoded strings and anti-analysis. Complete, but the slowest successful run at 9.74 summed episode-hours.

18/20 valid

Claude Opus 5

Best injection-detail mean and strong technique recall. Two mid-analysis refusals reduced useful coverage.

18/20 valid

GPT-5.6 Sol

Best single score with no unsupported technique claims. Both Level 22 variants ended at the tool-call limit.

19/20 valid

DeepSeek V4 Flash

Strong bonus and encryption results, with greater variance, one budget exit, and the most unsupported claims.

20/20 valid

Gemini 3.6 Flash

Fastest complete run and strong metadata recovery. Exact decoded-string and technique detail were weaker.

Policy coverage outcome: Claude Fable 5 refused all 20 artifacts before using a tool. That result is operationally relevant, but it is not a clean measure of reverse-engineering knowledge.
Show the failure taxonomy

Broad identification

The technique family was recognized, but required implementation details were missing.

Unsupported claims

APIs, techniques, configuration values, or execution steps were reported without recovered evidence.

Incomplete chains

Individual components were found but not connected into the correct execution sequence.

Budget exhaustion

Low-value exploration consumed the fixed call budget before a complete answer was produced.

Premature stopping

An early hypothesis was reported before critical details were verified.

Refusal

A valid defensive analysis task ended without a gradable answer.

Useful for orientation. Less reliable for exact reconstruction.

Models were better at identifying the shape of a program than recovering the details required for a final incident conclusion.

Stronger capabilities

What agents often recovered

  • Broad injection and execution techniques
  • Common Windows APIs, imports, strings, and constants
  • Initial behavioral hypotheses and recognizable persistence or evasion patterns
  • Straightforward control-flow relationships
Weaker capabilities

What remained brittle

  • Complete multi-stage execution chains
  • Exact decoded configuration, keys, and transformations
  • Indirect or dynamically resolved APIs
  • Distinguishing active logic from decoys without unsupported claims
Recommended use: analyst-assisted triage, prioritization, and hypothesis generation. No model recovered the true Level 23 C2 endpoint, and unreviewed output should not be treated as authoritative configuration recovery.

What Version 3 does—and does not—establish.

Measured

Command-line static analysis

Agents worked from isolated binaries with fixed tools and budgets. The benchmark does not measure dynamic analysis, debugging, or interactive decompiler workflows.

Observed once

No repeated-run variance

Each model-artifact pair was evaluated once, so results characterize the recorded runs rather than a stable population mean.

Controlled suite

Synthetic known-ground-truth artifacts

Deterministic grading is possible because behavior is known, but the suite does not reproduce the full diversity of real-world malware.

Every published score is traceable to evidence.

Each result can be followed from input artifact to agent transcript, tool output, final answer, deterministic grader decision, and aggregate score.

Environment

Static, binary-only analysis

One anonymized PE per isolated workspace. No source, Internet, debugger, decompiler, compilation, or dynamic execution.

Scoring

Deterministic ground truth

No LLM judge. Terminal refusals and budget exits remain in the aggregates. Main is the broad score; Level 23 supplies the separate Bonus.

Audit

Fully reproducible

All 120 answers were rescored, all six aggregates reconciled, and the 366-file checksum ledger and artifact hashes passed verification.

Independent check: run python3 version3/verify.py from the repository root. It requires no API key or model call.

Frontier agents are becoming capable binary analysts—not yet dependable reverse engineers.

Current agents can accelerate orientation and hypothesis generation. Exact reconstruction still requires stronger tool planning, longer-horizon evidence tracking, better calibration, efficient budget use, and expert verification.

For security teams

Use agents as accelerators

Apply them to triage, prioritization, and evidence discovery while retaining analyst review for configuration, attribution, and consequential conclusions.

For model developers

Reward verifiable recovery

Optimize for evidence-grounded technical facts, efficient tool paths, uncertainty reporting, and completion reliability—not broader descriptions alone.