apt37-reaper

apt37-reaper is a skill for Claude Code from PurpleAILAB/Decepticon. It costs 53 tokens per session (6,117 once invoked), scanned A, original, Apache-2.0.

A cybersecurity profile for simulating the methods of APT37, a North Korean group known for spying through targeted attacks.

In plain words
What is it for?
It is for planning adversary simulations, checking defensive monitoring, and studying APT37's targets, malware, documents, exploits, and communication methods.
Why use it?
It gives security teams a documented model of one real-world attacker, so they can test whether their systems detect similar activity.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Good fit It is for planning adversary simulations, checking defensive monitoring, and studying APT37's targets, malware, documents, exploits, and communication methods.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/purpleailab/decepticon/apt37-reaper
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 · 5,471 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 apt37-reaper
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 apt37-reaper

README.md
[![agentmods](https://agentmods.dev/badge/skills/purpleailab/decepticon/apt37-reaper/github.svg)](https://agentmods.dev/skills/purpleailab/decepticon/apt37-reaper)
Your own site
<a href="https://agentmods.dev/skills/purpleailab/decepticon/apt37-reaper"><img src="https://agentmods.dev/badge/skills/purpleailab/decepticon/apt37-reaper/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 apt37-reaper

Your own site · 80×15
<a href="https://agentmods.dev/skills/purpleailab/decepticon/apt37-reaper"><img src="https://agentmods.dev/badge/skills/purpleailab/decepticon/apt37-reaper.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 53 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 6,117 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 critical

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 →

  • critical YARA Match · line 153
    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 Privilege Escalation · line 155
    Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.
    Fix: Remove references to credential paths. Use environment variables or secrets managers. For docs, use placeholder paths (e.g., /path/to/config). Never load .env or token files in production code paths.
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 $0.00053 $0.06117
Opus 5 $0.00026 $0.03059
Sonnet 5 $0.00011 $0.01223
Haiku 4.5 $0.00005 $0.00612

Measured 10d ago against content hash 7793b9a233ac, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

apt37-reaper 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 10d 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/apt37-reaper/SKILL.md · 189 lines

How it starts

The opening of the file, as written. The whole thing — 189 lines — stays where its author put it; the contents beside it link to each section on GitHub.

APT37 (Reaper, ScarCruft, Ricochet Chollima, InkySquid) — Adversary Emulation Profile

APT37 (MITRE ATT&CK G0067) is a North Korean state-sponsored cyber-espionage group active since at least 2012. Tracked as ScarCruft (Kaspersky), Reaper (FireEye), InkySquid (Volexity), Group123 (Cisco Talos), TEMP.Reaper, and Ricochet Chollima (CrowdStrike), APT37 primarily targets South Korean government, military, media, and defector communities, with expanding operations into Japan, Vietnam, the Middle East, and Europe. The group is characterized by aggressive exploitation of zero-day vulnerabilities in Adobe Flash Player, Internet Explorer, and Microsoft Edge; heavy use of weaponized Hangul Word Processor (HWP) documents; strategic web compromises (watering holes); a diverse custom malware arsenal (RoKRAT, BLUELIGHT, Chinotto, Dolphin, DOGCALL); and C2 over legitimate cloud services (Dropbox, pCloud, Yandex, Box, Google Drive). Unlike the higher-profile Lazarus Group, APT37 focuses on targeted intelligence collection and defector surveillance rather than financial theft or destructive operations.

Attribution & motivation

  • Sponsor / nation: Democratic People's Republic of Korea (North Korea) — Reconnaissance General Bureau (RGB). FireEye's 2018 report assessed APT37 as a North Korean state-sponsored group with "high confidence," based on malware compilation timestamps aligned with Pyongyang working hours (UTC+8:30/+9), Korean-language resources in binaries, targeting patterns consistent with DPRK state interests, and overlapping infrastructure with other attributed DPRK operations.
  • Motivation: Primarily strategic intelligence collection (espionage) — surveillance of North Korean defectors, journalists covering DPRK affairs, and human-rights activists; collection of South Korean military, government, and diplomatic intelligence. Secondary missions include pre-positioning for destructive operations (MBR-wiping malware capability) and technology/defense intelligence collection from aerospace, chemicals, electronics, and manufacturing sectors.
  • Attribution confidence: High. FireEye's 2018 "APT37: The Overlooked North Korean Actor" report, Kaspersky's ScarCruft tracking (Operation Daybreak, Bluetooth harvester), Cisco Talos "Korea in the Crosshairs," Volexity's InkySquid browser-exploit research, and consistent multi-vendor reporting over a decade.

Read the full file on GitHub · 189 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. 10d ago First seen · 189 lines · 53 tokens per session scan A 7793b9a233ac

Subscribe to this mod's changes

apt37-reaper is a skill published in the GitHub repository PurpleAILAB/Decepticon (5,471 stars, last pushed 10d ago), licensed Apache-2.0. It adds 53 tokens to every session and 6,117 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.