kimsuky-velvet-chollima

kimsuky-velvet-chollima is a skill for Claude Code from PurpleAILAB/Decepticon. It costs 66 tokens per session (8,298 once invoked), scanned A, original, Apache-2.0.

A cybersecurity profile of Kimsuky, a North Korean cyber-espionage group also known by names such as APT43 and Emerald Sleet.

In plain words
What is it for?
Use it for authorized security research, threat analysis, detection planning, or controlled adversary-emulation exercises involving Kimsuky.
Why use it?
It gives agents background for studying or imitating the group's targets, social-engineering methods, and known malware and credential-theft techniques.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Good fit Use it for authorized security research, threat analysis, detection planning, or controlled adversary-emulation exercises involving Kimsuky.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/purpleailab/decepticon/kimsuky
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 kimsuky
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 kimsuky-velvet-chollima

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

Your own site · 80×15
<a href="https://agentmods.dev/skills/purpleailab/decepticon/kimsuky"><img src="https://agentmods.dev/badge/skills/purpleailab/decepticon/kimsuky.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 66 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 8,298 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: 9 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 Prompt Injection · line 3
    This content may contain harmful instructions that could cause physical harm if followed. CRITICAL: Review carefully before use.
    Fix: Remove all content that could lead to harmful outcomes. Add safety guardrails and human oversight for any high-risk operations.
  • critical Prompt Injection · line 7
    This content may contain harmful instructions that could cause physical harm if followed. CRITICAL: Review carefully before use.
    Fix: Remove all content that could lead to harmful outcomes. Add safety guardrails and human oversight for any high-risk operations.
  • critical Prompt Injection · line 12
    This content may contain harmful instructions that could cause physical harm if followed. CRITICAL: Review carefully before use.
    Fix: Remove all content that could lead to harmful outcomes. Add safety guardrails and human oversight for any high-risk operations.
  • critical Prompt Injection · line 8
    This content may contain harmful instructions that could cause physical harm if followed. CRITICAL: Review carefully before use.
    Fix: Remove all content that could lead to harmful outcomes. Add safety guardrails and human oversight for any high-risk operations.
  • high YARA Match · line 26
    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.
  • high YARA Match · line 52
    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 72
    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 216
    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.
  • medium Rogue Agent · line 80
    Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.
    Fix: Remove any persistence mechanisms (cron jobs, startup scripts, state files). Skills should not maintain state across sessions without explicit user consent.
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 $0.00066 $0.08298
Opus 5 $0.00033 $0.04149
Sonnet 5 $0.00013 $0.01660
Haiku 4.5 $0.00007 $0.00830

Measured 10d ago against content hash a7950eb87b17, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

kimsuky-velvet-chollima 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/kimsuky/SKILL.md · 250 lines

How it starts

The opening of the file, as written. The whole thing — 250 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Kimsuky (Velvet Chollima, Emerald Sleet, THALLIUM, Black Banshee, APT43) — Adversary Emulation Profile

Kimsuky (MITRE ATT&CK G0094) is a DPRK-based cyber-espionage group attributed to North Korea's Reconnaissance General Bureau (RGB), specifically the 63rd Research Center, operating since at least 2012. Initially focused on South Korean government entities and think tanks, the group has expanded its aperture to the United States, Japan, Russia, and Europe — consistently targeting individuals and organizations with insight into Korean Peninsula foreign policy, nuclear policy, sanctions, and defense issues. Kimsuky is distinguished by its heavy investment in social engineering and credential phishing over zero-day exploitation: the group impersonates journalists, researchers, diplomats, and think-tank personnel in long-running correspondence campaigns to build trust before delivering malicious payloads or harvesting credentials. Its tooling ranges from commodity RATs (QuasarRAT, gh0st RAT) to a stable of bespoke malware families (BabyShark, AppleSeed, Gold Dragon, KONNI, Troll Stealer) and malicious browser extensions (TRANSLATEXT). Since 2023, Kimsuky has been observed leveraging commercial LLMs for target research and vulnerability analysis, and adopting ClickFix-style social engineering to trick victims into self-executing malicious PowerShell.

Attribution & motivation

  • Sponsor / nation: Democratic People's Republic of Korea (DPRK) — Reconnaissance General Bureau (RGB), 63rd Research Center. U.S. government (CISA/FBI/CNMF joint advisory AA20-301A, 2020) and multiple vendor assessments (Mandiant/Google TAG, CrowdStrike, Microsoft, Symantec) attribute Kimsuky operations to North Korean state-sponsored actors. In 2023, the U.S. Treasury sanctioned Kimsuky as an entity of the RGB.
  • Motivation: Primarily strategic intelligence collection (espionage) — gathering foreign policy, nuclear/defense, and sanctions intelligence for the DPRK regime. Secondary motivation includes financial theft (cryptocurrency theft and laundering to self-fund operations, per Mandiant's APT43 report) and limited influence operations (DMARC abuse for impersonation campaigns).
  • Attribution confidence: High. Supported by U.S. government joint advisories (AA20-301A), FBI IC3 public service announcements (2026), Treasury OFAC sanctions designations, and consistent multi-vendor reporting (Mandiant, CrowdStrike, Microsoft, Symantec, Kaspersky, Malwarebytes, Cisco Talos, Proofpoint, Zscaler).

Read the full file on GitHub · 250 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 · 250 lines · 66 tokens per session scan A a7950eb87b17

Subscribe to this mod's changes

kimsuky-velvet-chollima is a skill published in the GitHub repository PurpleAILAB/Decepticon (5,471 stars, last pushed 10d ago), licensed Apache-2.0. It adds 66 tokens to every session and 8,298 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.