apt33-elfin

apt33-elfin is a skill for Claude Code from PurpleAILAB/Decepticon. It costs 55 tokens per session (4,357 once invoked), scanned A, original, Apache-2.0.

A cybersecurity profile of APT33, also called Elfin or Peach Sandstorm, mapped to MITRE ATT&CK, a framework for describing attacker behavior.

In plain words
What is it for?
Use it to study APT33's attributed activity, review its tactics and tools, and plan adversary-emulation work within an approved engagement.
Why use it?
It organizes known information about this suspected Iranian state-sponsored espionage group and its techniques for authorized security exercises.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Good fit Use it to study APT33's attributed activity, review its tactics and tools, and plan adversary-emulation work within an approved engagement.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/purpleailab/decepticon/apt33-elfin
About the project

Decepticon is an autonomous red-team agent that coordinates AI agents, security tools, sandboxes, and supporting services for authorized cybersecurity assessments. Security researchers and red teams can run it through its Docker stack, cloud service, command-line interface, or Python SDK, with the catalogue entries representing its available skills.

PurpleAILAB/Decepticon · 5,463 stars · on GitHub · decepticon.red

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.

Any agent
npx skills add PurpleAILAB/Decepticon --skill apt33-elfin
Clone the repo
git clone --depth 1 https://github.com/PurpleAILAB/Decepticon

Made for: Claude Code.

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 apt33-elfin

README.md
[![agentmods](https://agentmods.dev/badge/skills/purpleailab/decepticon/apt33-elfin/github.svg)](https://agentmods.dev/skills/purpleailab/decepticon/apt33-elfin)
Your own site
<a href="https://agentmods.dev/skills/purpleailab/decepticon/apt33-elfin"><img src="https://agentmods.dev/badge/skills/purpleailab/decepticon/apt33-elfin/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for apt33-elfin

Your own site · 80×15
<a href="https://agentmods.dev/skills/purpleailab/decepticon/apt33-elfin"><img src="https://agentmods.dev/badge/skills/purpleailab/decepticon/apt33-elfin.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 55 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,357 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 2 findings, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high YARA Match · line 67
    YARA rule matched a known malware signature (reverse shell, backdoor, ransomware, C2 framework, or info stealer).
    Fix: Remove the malware payload or compromised file entirely. Investigate how it entered the skill and audit all other artifacts for additional indicators of compromise.
  • high YARA Match · line 119
    YARA rule matched a hack tool or exploit indicator (offensive tools, reconnaissance, privilege escalation, or exploit frameworks).
    Fix: Remove offensive tool references and exploit code. Legitimate agent skills should not contain penetration testing tools, exploit frameworks, or reconnaissance utilities.
How audits are shown
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 5.1 $0.00055 $0.04357
Opus 5 $0.00028 $0.02178
Sonnet 5 $0.00011 $0.00871
Haiku 4.5 $0.00006 $0.00436

Measured 9d ago against content hash 98f87dbfe461, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

apt33-elfin scanned grade A with 0 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 9d 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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

packages/decepticon/decepticon/skills/shared/adversary-emulation/apt33-elfin/SKILL.md · 149 lines

How it starts

The opening of the file, as written. The whole thing — 149 lines — stays where its author put it; the contents beside it link to each section on GitHub.

APT33 (Elfin, Peach Sandstorm, HOLMIUM) — Adversary Emulation Profile

APT33 (MITRE ATT&CK G0064; aliases Elfin, Peach Sandstorm, HOLMIUM) is a suspected Iranian state-sponsored threat group that has conducted cyber-espionage operations since at least 2013. The group is best known for spearphishing-driven intrusions against the aviation, energy, and petrochemical sectors in the United States, Saudi Arabia, and South Korea, and for an enduring evolution from .hta-based phishing toward large-scale cloud-identity attacks. Its operations blend publicly available offensive tooling with custom backdoors, and the group has been linked — with varying confidence — to destructive wiper malware. This profile maps APT33's documented TTPs to ATT&CK and provides emulation guidance for Decepticon under authorized engagement scope.

Attribution & motivation

  • Suspected sponsor / nation: Iran. FireEye/Mandiant assessed APT33 works at the behest of the Iranian government and reported evidence linking the group to the Nasr Institute, an Iranian organization associated with cyber-warfare operations. Microsoft tracks the same actor as Peach Sandstorm and likewise attributes it to Iranian state interests.
  • Primary motivation: Strategic espionage / intelligence collection aligned with Iranian state interests (aerospace, defense, energy). Microsoft assessed the 2023 password-spray campaign was likely intended to facilitate intelligence collection supporting Iranian state objectives.
  • Secondary / destructive dimension: APT33 has been linked to the StoneDrill wiper, which shares similarities with the Shamoon family used against Saudi Aramco and RasGas (2012). Confidence on the destructive link is lower than the espionage attribution — Kaspersky and FireEye both noted it is unproven whether the Shamoon and StoneDrill operators are the same group or merely aligned in interests/region. Treat any destructive capability claim as plausible-but-unconfirmed.
  • Attribution confidence: Moderate-to-high for Iranian state-sponsored espionage (multiple independent vendors converge: FireEye/Mandiant, Symantec, Microsoft). Lower for the destructive/wiper attribution.

Read the full file on GitHub · 149 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. 9d ago First seen · 149 lines · 55 tokens per session scan A 98f87dbfe461

Subscribe to this mod's changes

apt33-elfin is a skill published in the GitHub repository PurpleAILAB/Decepticon (5,463 stars, last pushed 9d ago), licensed Apache-2.0. It adds 55 tokens to every session and 4,357 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.