infostealer-malware-detector

infostealer-malware-detector is a skill for Codex from PracticalSwan/agent-skills. It costs 115 tokens per session (2,334 once invoked), scanned A, original, MIT.

A workflow for finding and checking infostealer malware, which is malicious software that steals passwords, tokens, and other sensitive data from a computer.

In plain words
What is it for?
Use it to search for suspected stealers, compare file hashes with public threat databases, and document or quarantine confirmed threats.
Why use it?
It provides a way to investigate suspected credential theft and verify suspicious files before removing them.

Skill for Codex

Written for Codex: reads ~/.codex or $CODEX_HOME. Also seen: mentions subagents; mentions Claude Code; mentions Codex.

Good fit Use it to search for suspected stealers, compare file hashes with public threat databases, and document or quarantine confirmed threats.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/practicalswan/agent-skills/infostealer-malware-detector
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 PracticalSwan/agent-skills --skill infostealer-malware-detector
Clone the repo
git clone --depth 1 https://github.com/PracticalSwan/agent-skills

Made for: Codex.

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 infostealer-malware-detector

README.md
[![agentmods](https://agentmods.dev/badge/skills/practicalswan/agent-skills/infostealer-malware-detector/github.svg)](https://agentmods.dev/skills/practicalswan/agent-skills/infostealer-malware-detector)
Your own site
<a href="https://agentmods.dev/skills/practicalswan/agent-skills/infostealer-malware-detector"><img src="https://agentmods.dev/badge/skills/practicalswan/agent-skills/infostealer-malware-detector/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 infostealer-malware-detector

Your own site · 80×15
<a href="https://agentmods.dev/skills/practicalswan/agent-skills/infostealer-malware-detector"><img src="https://agentmods.dev/badge/skills/practicalswan/agent-skills/infostealer-malware-detector.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 115 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,334 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. 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: 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 Prompt Injection · line 178
    Hidden instructions were detected in comments or invisible text. These could contain malicious directives. Manual review is recommended.
    Fix: Audit all comments and invisible characters. Remove any instructions that direct the agent to perform unauthorized actions. Use plain, reviewable content.
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 $0.00115 $0.02334
Opus 5 $0.00057 $0.01167
Sonnet 5 $0.00023 $0.00467
Haiku 4.5 $0.00012 $0.00233

Measured 4d ago against content hash f9dc18cdff99, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

infostealer-malware-detector 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 4d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/hash-checker.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -s --request GET "https://www.virustotal.com/api/v3/files/${HASH}" --header "x-apikey: $VT_API_KEY"
infostealer-malware-detector/SKILL.md · 209 lines

How it starts

The opening of the file, as written. The whole thing — 209 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Infostealer Malware Detector & Remover (v1.1)

Tech Stack Target / Version: Windows Defender CLI, VirusTotal, MalwareBazaar, Python 3.8+, and cross-platform shell tooling.

Overview

This skill gives OpenClaw a complete workflow to search every file on the system, identify infostealer indicators, compute secure hashes, and verify them against live public databases.

Core principles (strict)

  • Primary detection: Targeted file search + SHA-256 hashing + VirusTotal/MalwareBazaar checks.
  • AV usage: Windows Defender (mpcmdrun.exe) or any other AV is permitted only when necessary (hash checks inconclusive, high suspicion remains, or user explicitly requests deeper scan).
  • Never default to AV – the agent must complete the full custom hash workflow first and document why AV escalation is needed.
  • Full user confirmation required before any quarantine or AV scan.
  • Full audit trail and quarantine before removal.

When to activate automatically

  • "My passwords are being stolen"

  • "Scan for infostealer / stealer malware"

  • "Check if RedLine / Vidar / Lumma is on my PC"

  • "Clean my system" (but follow custom-first rule)

  • Leverage native parallel subagent dispatch and 200k+ context windows where available.

Prerequisites

  • Internet connection (for hash lookups)
  • Optional but highly recommended: free VirusTotal API key (VT_API_KEY)
  • Python 3.8+ (for scripts/hash-checker.py)
  • Admin/root privileges for full system scan
  • Windows Defender enabled by default on Windows (no installation needed)

Step-by-Step Workflow (Custom Method First – Always)

Step 1: Scope the System & Identify High-Risk Areas

Run targeted discovery (fast & effective for infostealers):

# Windows (PowerShell)
Get-ChildItem -Path "$env:TEMP","$env:APPDATA","$env:LOCALAPPDATA","C:\ProgramData","C:\Users\*\AppData" -Recurse -File -Include *.exe,*.dll,*.bat,*.ps1,*.vbs,*.js -ErrorAction SilentlyContinue | Select-Object FullName,LastWriteTime,Length

# macOS / Linux
find /tmp ~/Library /Library /Users/*/Library /var/tmp -type f \( -name "*.exe" -o -name "*.dylib" -o -name "*.so" -o -name "*.sh" \) -mtime -30 2>/dev/null

Read the full file on GitHub · 209 lines

Files

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.

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. 4d ago Changed f9dc18cdff99
  2. 6d ago Changed 43edd28f2a42
  3. 9d ago First seen · 209 lines · 115 tokens per session scan A c148fc2ec2bb

Subscribe to this mod's changes

infostealer-malware-detector is a skill published in the GitHub repository PracticalSwan/agent-skills (14 stars, last pushed 4d ago), licensed MIT. It adds 115 tokens to every session and 2,334 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

Related

Other skills, from other repositories

analyzing-malware-behavior-with-cuckoo-sandbox

Detonate malware samples in Cuckoo Sandbox to observe runtime behavior — process creation, file system and registry changes, network communications, and API calls — and generate behavioral reports for classification and IOC extraction. Use when a sample has passed static triage and needs dynamic/behavioral analysis…

mukul975/Anthropic-Cybersecurity-Skills · 93 tokens

analyzing-network-traffic-of-malware

Analyzes network traffic generated by malware during sandbox execution or live incident response to identify C2 protocols, data exfiltration channels, payload downloads, and lateral movement patterns using Wireshark, Zeek, and Suricata. Activates for requests involving malware network analysis, C2 traffic decoding…

mukul975/Anthropic-Cybersecurity-Skills · 81 tokens

edgeone skill scanner

A local static scanner that checks agent-skill files for security risks before they are installed or used. Static analysis examines files without running them.

Tencent/AI-Infra-Guard · 148 tokens

analyzing-linux-elf-malware

Analyze malicious Linux ELF binaries — botnets, cryptominers, ransomware, and rootkits targeting Linux servers, containers, and cloud infrastructure — through static analysis, dynamic tracing, and reverse engineering of x8664 and ARM samples. Use when investigating Linux malware, triaging a suspicious ELF binary…

mukul975/Anthropic-Cybersecurity-Skills · 82 tokens

agent-review

Critically review a Stencila agent and suggest improvements. Use when asked to review, audit, critique, evaluate, or improve an agent directory or AGENT.md file. Covers frontmatter validation, system instruction quality, configuration correctness, and adherence to the Agent schema.

stencila/stencila · 57 tokens

performing-cryptographic-audit-of-application

A cryptographic audit systematically reviews an application's use of cryptographic primitives, protocols, and key management to identify vulnerabilities such as weak algorithms, insecure modes, hardco.

xalgorix/xalgorix · 43 tokens