Fine-tune of Qwen3.5-9B-Claude-4.6-OS-Auto-Variable-HERETIC-UNCENSORED-THINKING by DavidAU, specialised in offensive and defensive security work. Trained on a distilled corpus of 15,611 knowledge units covering bug bounty, web pentesting, traffic analysis, DFIR, memory forensics and incident response.
Designed to assist researchers in real engagements on bug bounty platforms (HackerOne, Bugcrowd, Intigriti, YesWeHack, Immunefi) with operational rules baked in: authorized scope only, minimal non-destructive PoCs, callbacks to owned infrastructure. Answers in Spanish; payloads, commands and report templates are in English.
Format and download
Two files:
qwen3.5-9b-claude-4.6-os-av-h-uncensored-think-d_au-imat-bughunter-v6.Q4_K_M.gguf — the LLM, ~5.3 GB (Q4_K_M with calibrated imatrix).
mmproj-F32.gguf — the vision projector, ~1.7 GB. Download this only if you want image understanding. Place it in the same folder as the LLM.
Vision is inherited from the DavidAU base and untouched by the fine-tune (the vision tower and projector were not trained). The mmproj-F32.gguf published here is the same one DavidAU ships with the base, so it works identically. Do note that our fine-tune corpus is 100% text, so the LLM is not specifically tuned to reason over images — it can describe them and answer basic visual questions, but its added value is on the text side.
Any runtime that supports GGUF (KoboldCpp, Text Generation WebUI, etc.)
Capabilities
Red team / offensive security
Covers the full lifecycle of a bug bounty engagement:
Reconnaissance: passive subdomain enumeration, attack-surface mapping, API mapping, secret extraction from JavaScript, throttled use of httpx/gau/katana.
Web vulnerabilities: root patterns and sub-patterns for IDOR/BOLA, SSRF, CSRF, XSS (reflected/stored/DOM/blind/mXSS), SQL injection across contexts, misconfigured CORS, chainable open redirects into OAuth, prototype pollution, subdomain takeover, path traversal, LFI/RFI, HTTP request smuggling (CL.TE, TE.CL, H2 desync, single-packet attack), cache poisoning and deception.
APIs: BOLA, BFLA, excessive data exposure, legacy versions without authz, GraphQL endpoints with introspection, alias abuse, batching to skip rate limits.
Server-side: SSRF to cloud metadata (AWS IMDSv1/v2, GCP, Azure), SSTI ({{7*7}} on Jinja/Twig/Freemarker/Velocity), RCE via deserialization, XXE in SAML/SOAP/SVG/OOXML.
When a system prompt is provided, the model incorporates ethical research rules:
In-scope assets only, verified against the program scope before every request.
Sustained throughput ≤1-2 req/s. Bursts only for race conditions or authorised OTP brute-force.
Minimal non-destructive PoC: whoami/id for RCE; SELECT version() for SQLi; two owner accounts for IDOR.
OOB callbacks always to owned infrastructure. Never to shared third-party services.
Never use credentials, tokens or API keys found in a finding to validate access.
Cloud metadata: proving access is enough. Never exfiltrate IAM credentials.
Minimum reportable severity: High or Critical (except in a chain, when Low is explicitly bountied, or in humanitarian VDPs).
How it was trained
Data
14,914 examples in ShareGPT format (train), 466 valid, 309 test. Extracted from 1,690 source documents grouped into 9 sources with weighted sampling to prioritise specialised offensive content:
Source
Weight
% in train
Patterns distilled from real HackerOne reports
×4
7.9%
Reproducible PortSwigger Web Security Academy methods
×3
6.6%
Factual HackerOne reports (by category)
×3
3.5%
Researcher's own tooling
×3
12.9%
Lab walkthroughs
×2
5.5%
Structured offensive skills
×2
20.8%
Mixed skills (offensive + defensive)
×1.5
12.1%
CTF write-ups
×1
8.6%
Defensive / governance / patch management skills
×0.35
21.6%
Additional: 72 short conversational examples (greetings, meta-questions, ambiguous requests that get answered by asking back) to prevent format collapse — the model learns to modulate length based on the question rather than dumping methodology for any input.
Three-thirds system prompt setup:
33% of examples with no system prompt (the model works well without it)
33% with a long system prompt (the full operational ruleset)
33% with one of six short variants
This prevents the model from becoming dependent on the exact wording of a specific system prompt.
Hyperparameters
Key configuration aligned with what worked in similar prior work (learned after several previous attempts that failed due to format collapse):
Parameter
Value
Learning rate
1e-5 (low; avoids format memorisation)
Epochs
1 (0.54 effective epochs — learn without overfitting)
Framework: LLaMA-Factory on Colab A100 80GB (~5h 15min).
Training metrics
Healthy loss curve, no overfitting:
Step
train_loss
eval_loss
100
~1.95
1.893
400
~1.75
1.698
700
~1.65
1.630
1000
~1.60
1.588
1500
~1.57
1.561
1600
~1.55
1.559
final (1865)
1.6783
~1.55
The eval_loss stayed at or below train_loss throughout, indicating real learning without formatting overfit.
Post-processing
LoRA adapter merge with the base model (llamafactory-cli export).
GGUF F16 conversion via convert_hf_to_gguf.py from llama.cpp.
Imatrix generation using 200 chunks of the standard Bartowski v3 calibration corpus (Wikipedia + code + technical prose).
Final quantization to Q4_K_M with imatrix (5.3 GB).
Chat template patched to accept multiple system messages (compatibility with clients that send their own system + an additional one, common in AI-enabled IDEs).
Hygiene and sanitisation
The source corpus went through blocking PII auditing in two layers (extraction and final build). Sanitised:
Ephemeral PortSwigger Web Security Academy lab IDs
OpenAI-compatible endpoint at http://127.0.0.1:8080/v1/chat/completions.
Recommended system prompt
You can use the model without a system prompt (it behaves correctly by default). For bug bounty tasks specifically, the recommended prompt is:
You are a professional bug bounty researcher. You work on HackerOne, Bugcrowd, Intigriti, YesWeHack, Immunefi and independent programs.
Inviolable rules:
- In-scope assets only, verified against the program scope before every request.
- Sustained throughput ≤1-2 req/s.
- Minimal non-destructive PoC.
- OOB callbacks always to owned infrastructure.
- Never use credentials or tokens found in a finding to validate access.
- Minimum reportable severity: High or Critical.
Answer in Spanish. Payloads, commands and report templates in English.
For fine-tuners: LoRA adapter available in /adapter
If you want to build on top of this fine-tune — for example adding another language, composing with a different domain LoRA, or re-merging with different quantization settings — the LoRA adapter used to train this model is published inside this same repo under /adapter:
Option B — keep as adapter and compose with another LoRA:
python
1model = PeftModel.from_pretrained(base,f"{adapter_dir}/adapter", adapter_name="bughunter")2model.load_adapter("your-org/your-language-lora", adapter_name="lang")3model.set_adapter(["bughunter","lang"])# both active
Notes when composing:
Keep new LoRAs in a similar rank range (8-32 works well).
Keep the patched chat_template.jinja if you rely on IDE agents that inject their own system messages; otherwise the DavidAU original works fine.
Tool calling is weak in this fine-tune (no tool_call examples in the training corpus). Set temperature=0.1 and top_p=0.9 on the client to compensate.
Known limitations
Uncensored model. Based on DavidAU's decensoring work over Qwen3.5-9B. The additional fine-tune reinforces the ethical researcher role, but the user is responsible for using it within applicable law and authorised scope.
Fine-tuned on a 100% text dataset. Vision comes from the base's untouched mmproj — image understanding works, but the fine-tune does not add domain-specific visual reasoning.
Corpus mostly in Spanish with English technical terminology. It may be less fluent for pure-English technical conversation.
Source corpus bias: distilled material prioritises web and API vulnerabilities. Coverage of other domains (ICS/SCADA, low-level wireless, hardware hacking) is limited.
NOT A SUBSTITUTE FOR PRIMARY RESEARCH. The model can replay learned patterns but does not discover on its own. Use it as an assistant that speeds up the researcher's work, not as an oracle.
Hallucination of CVEs, URLs and tool names. Always verify any concrete reference before using it.
Ethical and legal use
This model is distributed for:
Authorised research within bug bounty programs offering Safe Harbor.
Pentesting under a signed services contract.
CTFs and lab environments you own or are authorised to use.
Cybersecurity education.
Academic research.
It is not distributed for:
Attacking systems without explicit authorisation.
Commercial exploitation of vulnerabilities found outside bounty programs.
Malware development for distribution.
Any activity that violates the applicable law in your jurisdiction.
The user assumes all legal responsibility for the use of the model.
@misc{qwen35_bughunter_v6,
title = {qwen3.5-9b-claude-4.6-os-av-h-uncensored-think-d_au-imat-bughunter-v6: Fine-tune specialised in bug bounty and offensive/defensive security},
year = {2026},
base = {DavidAU/Qwen3.5-9B-Claude-4.6-OS-Auto-Variable-HERETIC-UNCENSORED-THINKING},
method = {LoRA fine-tune, rank=8, lr=1e-5, 1 epoch, QLoRA 4-bit},
data = {14914 ShareGPT examples distilled from public bug bounty corpus}
}