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
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.
npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill analyzing-persistence-mechanisms-in-linuxgit clone --depth 1 https://github.com/mukul975/Anthropic-Cybersecurity-SkillsWrote 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/analyzing-persistence-mechanisms-in-linux)<a href="https://agentmods.dev/skills/mukul975/anthropic-cybersecurity-skills/analyzing-persistence-mechanisms-in-linux"><img src="https://agentmods.dev/badge/skills/mukul975/anthropic-cybersecurity-skills/analyzing-persistence-mechanisms-in-linux/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/analyzing-persistence-mechanisms-in-linux"><img src="https://agentmods.dev/badge/skills/mukul975/anthropic-cybersecurity-skills/analyzing-persistence-mechanisms-in-linux.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 4 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 40 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.
- medium Rogue Agent · line 3 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.
- medium Rogue Agent · line 40 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.
- medium Privilege Escalation · line 52 Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.Fix: Avoid sudo/root unless strictly required. Prefer least-privilege patterns. If elevation is needed, document the justification and scope.
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 | $0.00082 | $0.00735 |
| Opus 5 | $0.00041 | $0.00367 |
| Sonnet 5 | $0.00016 | $0.00147 |
| Haiku 4.5 | $0.00008 | $0.00073 |
Grade A, and why
analyzing-persistence-mechanisms-in-linux scanned grade A with 1 finding 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 12d 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.
Asks for rootlowPrivilege escalation
A mod that escalates privileges can change anything on the machine, not only the project.
- Root or sudo access on target Linux system (or forensic image) Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.
Copies of this mod
7 near-identical copies found in the catalogue:
- analyzing-persistence-mechanisms-in-linux — 100% identical, 0 lines differ
- analyzing-persistence-mechanisms-in-linux — 88% identical, 30 lines differ
- analyzing-persistence-mechanisms-in-linux — 88% identical, 30 lines differ
- analyzing-persistence-mechanisms-in-linux — 86% identical, 38 lines differ
- analyzing-persistence-mechanisms-in-linux — 86% identical, 4 lines differ
- analyzing-persistence-mechanisms-in-linux — 86% identical, 4 lines differ
- analyzing-persistence-mechanisms-in-linux — 84% identical, 4 lines differ
How it starts
The opening of the file, as written. The whole thing — 73 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Analyzing Persistence Mechanisms in Linux
Overview
Adversaries establish persistence on Linux systems through crontab jobs, systemd service/timer units, LD_PRELOAD library injection, shell profile modifications (.bashrc, .profile), SSH authorized_keys backdoors, and init script manipulation. This skill scans for all known persistence vectors, checks file timestamps and integrity, and correlates findings with auditd logs to build a timeline of persistence installation.
When to Use
- When investigating security incidents that require analyzing persistence mechanisms in linux
- When building detection rules or threat hunting queries for this domain
- When SOC analysts need structured procedures for this analysis type
- When validating security monitoring coverage for related attack techniques
Prerequisites
- Root or sudo access on target Linux system (or forensic image)
- auditd configured with file watch rules on persistence paths
- Python 3.8+ with standard library (os, subprocess, json)
- Optional: OSSEC/Wazuh agent for file integrity monitoring alerts
Steps
- Scan Crontab Entries — Enumerate all user crontabs, /etc/cron.d/, /etc/cron.daily/, and anacron jobs for suspicious commands
- Audit Systemd Units — Check /etc/systemd/system/ and ~/.config/systemd/user/ for non-package-managed service and timer units
- Detect LD_PRELOAD Hijacking — Check /etc/ld.so.preload and LD_PRELOAD environment variable for injected shared libraries
- Inspect Shell Profiles — Scan .bashrc, .bash_profile, .profile, /etc/profile.d/ for injected commands or reverse shells
- Check SSH Authorized Keys — Audit all authorized_keys files for unauthorized public keys with command restrictions
- Correlate Auditd Logs — Search auditd logs for file modification events on persistence paths to build an installation timeline
- Generate Persistence Report — Produce a risk-scored report of all discovered persistence mechanisms
Expected Output
What ships with it
3 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.
- 12d ago First seen · 73 lines · 82 tokens per session scan A de87f57bc4f9
analyzing-persistence-mechanisms-in-linux is a skill published in the GitHub repository mukul975/Anthropic-Cybersecurity-Skills (32,631 stars, last pushed 12d ago), licensed Apache-2.0. It adds 82 tokens to every session and 735 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 1 finding (asks for root). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
analyzing-persistence-mechanisms-in-linux
Detect and analyze Linux persistence mechanisms including crontab entries, systemd service units, LDPRELOAD hijacking, bashrc modifications, and authorizedkeys backdoors using auditd and file integrity monitoring.
analyzing-persistence-mechanisms-in-linux
A guide to finding ways attackers can make Linux programs or accounts start again automatically after a restart or login. It examines scheduled tasks, system services, shell startup files, injected libraries, and SSH keys.
analyzing-persistence-mechanisms-in-linux
Detect and analyze Linux persistence mechanisms including crontab entries, systemd service units, LDPRELOAD hijacking, bashrc modifications, and authorizedkeys backdoors using auditd and file integrity monitoring.
analyzing-persistence-mechanisms-in-linux
Scan Linux systems for persistence mechanisms including crontab/systemd entries, LDPRELOAD injection, shell profile modifications (.bashrc, .profile), and SSH authorizedkeys backdoors, then correlate findings with auditd logs into an installation timeline. Use during incident response or threat hunting to detect or…
analyzing-persistence-mechanisms-in-linux
Detect and analyze Linux persistence mechanisms including crontab entries, systemd service units, LDPRELOAD hijacking, bashrc modifications, and authorizedkeys backdoors using auditd and file integrity monitoring.
analyzing-persistence-mechanisms-in-linux
Detect and analyze Linux persistence mechanisms including crontab entries, systemd service units, LDPRELOAD hijacking, bashrc modifications, and authorizedkeys backdoors using auditd and file integrity monitoring.