Anthropic Cybersecurity Skills is a library of structured cybersecurity procedures for AI agents, covering security domains and mappings to established security frameworks. It is for authorized security analysis, penetration testing, incident response, research, defense, and education across compatible AI platforms. The catalogue entries package parts of this library as agent skills, instructions, or a plugin.
Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/mukul975/Anthropic-Cybersecurity-Skillsnpx agentmods add skills/mukul975/anthropic-cybersecurity-skills/abusing-shadow-credentials-for-privescWrote 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.
[](https://agentmods.dev/skills/mukul975/anthropic-cybersecurity-skills/abusing-shadow-credentials-for-privesc)<a href="https://agentmods.dev/skills/mukul975/anthropic-cybersecurity-skills/abusing-shadow-credentials-for-privesc"><img src="https://agentmods.dev/badge/skills/mukul975/anthropic-cybersecurity-skills/abusing-shadow-credentials-for-privesc/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.
<a href="https://agentmods.dev/skills/mukul975/anthropic-cybersecurity-skills/abusing-shadow-credentials-for-privesc"><img src="https://agentmods.dev/badge/skills/mukul975/anthropic-cybersecurity-skills/abusing-shadow-credentials-for-privesc.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Snyk pass
- NVIDIA SkillSpector warn
SkillSpector: 1 finding, 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 3 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.
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00097 | $0.02386 |
| Opus 5 | $0.00048 | $0.01193 |
| Sonnet 5 | $0.00019 | $0.00477 |
| Haiku 4.5 | $0.00010 | $0.00239 |
Grade A, and why
abusing-shadow-credentials-for-privesc 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 11d 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.
Copies of this mod
2 near-identical copies found in the catalogue:
- abusing-shadow-credentials-for-privesc — 100% identical, 0 lines differ
- abusing-shadow-credentials-for-privesc — 100% identical, 0 lines differ
How it starts
The opening of the file, as written. The whole thing — 186 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Abusing Shadow Credentials for Privilege Escalation
Legal Notice: This skill is for authorized security testing and educational purposes only. Shadow Credentials grant full takeover of the targeted account. Use only against systems you own or are explicitly authorized in writing to test. Unauthorized access is a crime.
Overview
The Shadow Credentials technique abuses the msDS-KeyCredentialLink attribute of Active Directory user and computer objects. This attribute stores raw public keys ("Key Credentials") used by Windows Hello for Business and Azure AD device registration for passwordless certificate-based logon via PKINIT (Public Key Cryptography for Initial Authentication in Kerberos). If an attacker has write permission over a target object's msDS-KeyCredentialLink — typically granted by GenericWrite, GenericAll, WriteProperty, or AddKeyCredentialLink ACEs surfaced in BloodHound — they can append their own attacker-generated public key. They then request a TGT for the target via PKINIT using the matching private key and recover the target's NT hash, achieving complete account takeover without resetting the password, which is far stealthier than a forced password reset.
The technique was published by Elad Shamir ("Shadow Credentials: Abusing Key Trust Account Mapping for Account Takeover") and implemented in the C# tool Whisker. The Python equivalent pyWhisker (ShutdownRepo) manipulates the attribute over LDAP, and Certipy integrates the entire chain via certipy shadow auto. The target environment must support PKINIT and have at least one Domain Controller running Windows Server 2016 or later. Sources: pyWhisker, Whisker, The Hacker Recipes — Shadow Credentials.
When to Use
- When BloodHound reveals
GenericWrite/GenericAll/AddKeyCredentialLinkover a higher-value user or computer - As a stealthier alternative to
ForceChangePassword(no password reset = less disruption/alerting) - To take over a computer account to chain into Resource-Based Constrained Delegation (RBCD)
- During red-team operations needing account takeover without locking out the legitimate user
- For purple-team exercises generating
msDS-KeyCredentialLinkmodification telemetry
What ships with it
4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 11d ago First seen · 186 lines · 97 tokens per session scan A 83ba5fe08bae
abusing-shadow-credentials-for-privesc is a skill published in the GitHub repository mukul975/Anthropic-Cybersecurity-Skills (32,541 stars, last pushed 11d ago), licensed Apache-2.0. It adds 97 tokens to every session and 2,386 once invoked, about $0.0005 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.
Other skills, from other repositories
abusing-shadow-credentials-for-privesc
Take over Active Directory accounts by writing attacker-controlled public keys to msDS-KeyCredentialLink (Shadow Credentials) with pyWhisker, Whisker, or Certipy, then authenticate via PKINIT to recover the target's NT hash without a password reset. Use when BloodHound shows…
abusing-shadow-credentials-for-privesc
Take over Active Directory accounts by writing attacker-controlled public keys to msDS-KeyCredentialLink (Shadow Credentials) with pyWhisker, Whisker, or Certipy, then authenticate via PKINIT to recover the target's NT hash without a password reset. Use when BloodHound shows…
conducting-internal-reconnaissance-with-bloodhound-ce
Conduct internal Active Directory reconnaissance using BloodHound Community Edition to map attack paths, identify privilege escalation chains, and discover misconfigurations in domain environments.
ad-killer
Use when active Directory and Windows domain exploitation for enterprise penetration testing. Use when attacking Windows domains, exploiting AD misconfigurations, or performing lateral movement in enterprise environments.
conducting-domain-persistence-with-dcsync
Perform DCSync attacks to replicate Active Directory credentials and establish domain persistence by extracting KRBTGT, Domain Admin, and service account hashes for Golden Ticket creation.
ad-exploitation
Active Directory exploitation skill — credential attacks, lateral movement, privilege escalation, and domain domination. Activate when the user wants to exploit an AD environment after enumeration, or mentions: Kerberoasting, AS-REP Roasting, pass-the-hash, pass-the-ticket, lateral movement, DCSync, Golden Ticket…