virustotal-api

virustotal-api is a skill for Claude Code from Liberty91LTD/cti-skills. It costs 23 tokens per session (828 once invoked), scanned A, original, MIT.

An API reference for VirusTotal, a service that compares files, domains, IP addresses, and URLs with security-analysis data. It covers authentication and endpoints for retrieving analysis results and related attributes.

In plain words
What is it for?
Use it to look up file hashes, IP addresses, domains, and URLs, then read detection counts, classifications, reputation, names, tags, and sandbox results.
Why use it?
It gives developers the request formats and response fields needed to query VirusTotal from code. This avoids manually checking the service when automated lookups are needed.

Skill for Claude Code

Written for Claude Code: user-invocable in frontmatter.

Good fit Use it to look up file hashes, IP addresses, domains, and URLs, then read detection counts, classifications, reputation, names, tags, and sandbox results.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/liberty91ltd/cti-skills/virustotal-api
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 Liberty91LTD/cti-skills --skill virustotal-api
Clone the repo
git clone --depth 1 https://github.com/Liberty91LTD/cti-skills

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 virustotal-api

README.md
[![agentmods](https://agentmods.dev/badge/skills/liberty91ltd/cti-skills/virustotal-api/github.svg)](https://agentmods.dev/skills/liberty91ltd/cti-skills/virustotal-api)
Your own site
<a href="https://agentmods.dev/skills/liberty91ltd/cti-skills/virustotal-api"><img src="https://agentmods.dev/badge/skills/liberty91ltd/cti-skills/virustotal-api/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 virustotal-api

Your own site · 80×15
<a href="https://agentmods.dev/skills/liberty91ltd/cti-skills/virustotal-api"><img src="https://agentmods.dev/badge/skills/liberty91ltd/cti-skills/virustotal-api.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 23 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 828 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.
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 $0.00023 $0.00828
Opus 5 $0.00012 $0.00414
Sonnet 5 $0.00005 $0.00166
Haiku 4.5 $0.00002 $0.00083

Measured 9d ago against content hash 54594bedc8e4, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

virustotal-api 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 9d 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.

Makes network callslowCapability

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

curl -s "https://www.virustotal.com/api/v3/files/{hash}" \
skills/virustotal-api/SKILL.md · 101 lines

How it starts

The opening of the file, as written. The whole thing — 101 lines — stays where its author put it; the contents beside it link to each section on GitHub.

VirusTotal API v3

Base URL

https://www.virustotal.com/api/v3

Authentication

Header: x-apikey: $VIRUSTOTAL_API_KEY

Check for key: echo $VIRUSTOTAL_API_KEY If empty, inform the user to run scripts/setup.sh or set the environment variable.

Rate Limits

  • Free: 4 requests/minute, 500/day, 15.5K/month
  • Premium: 1000 requests/minute

Key Endpoints

File Analysis

# Lookup by hash (MD5, SHA-1, SHA-256)
curl -s "https://www.virustotal.com/api/v3/files/{hash}" \
  -H "x-apikey: $VIRUSTOTAL_API_KEY"

Useful response fields:

  • data.attributes.last_analysis_stats — detection counts (malicious, suspicious, undetected)
  • data.attributes.popular_threat_classification — malware family
  • data.attributes.names — file names
  • data.attributes.type_description — file type
  • data.attributes.size — file size
  • data.attributes.tags — behavioral tags
  • data.attributes.sandbox_verdicts — sandbox results

IP Address

curl -s "https://www.virustotal.com/api/v3/ip_addresses/{ip}" \
  -H "x-apikey: $VIRUSTOTAL_API_KEY"

Useful fields: last_analysis_stats, as_owner, country, reputation, last_https_certificate

Relationships (communicating files, downloaded files, URLs):

curl -s "https://www.virustotal.com/api/v3/ip_addresses/{ip}/communicating_files?limit=10" \
  -H "x-apikey: $VIRUSTOTAL_API_KEY"

Domain

curl -s "https://www.virustotal.com/api/v3/domains/{domain}" \
  -H "x-apikey: $VIRUSTOTAL_API_KEY"

Useful fields: last_analysis_stats, registrar, creation_date, last_dns_records, reputation, categories

URL

URLs must be base64-encoded (without trailing =):

URL_ID=$(echo -n "https://example.com/path" | base64 | tr -d '=')
curl -s "https://www.virustotal.com/api/v3/urls/$URL_ID" \
  -H "x-apikey: $VIRUSTOTAL_API_KEY"

Common Query Patterns

Quick reputation check (any indicator type)

Return a summary: detection ratio, community score, key context.

Read the full file on GitHub · 101 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. 9d ago First seen · 101 lines · 23 tokens per session scan A 54594bedc8e4

Subscribe to this mod's changes

virustotal-api is a skill published in the GitHub repository Liberty91LTD/cti-skills (18 stars, last pushed 1mo ago), licensed MIT. It adds 23 tokens to every session and 828 once invoked, about $0.0001 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.