---
title: "Where our data comes from. Lazaretto"
description: "Every indicator source behind a Lazaretto verdict, with licence, refresh cadence, and an explicit statement of what each source cannot tell you."
url: "https://lazaretto.dev/sources"
---

[Home](https://lazaretto.dev/) / [Trust](https://lazaretto.dev/trust) / Sources

Provenance

# Where our data comes from

A verdict is only worth what the data behind it is worth. These are our sources, their licences, how fresh they are, and what each one genuinely cannot tell you.

**78,518** indicators held

**48** rules in 8 categories

**2026.09.26a** rules version

Newest indicator first seen **2026-10-06**.

## Sources

### abuse.ch URLhausCC0-1.0 (public domain)

Malware distribution URLs and domains. Used to match indicators embedded INSIDE a scanned artifact.

**Freshness:** Refreshed daily.

**What it cannot tell you:** Covers where malware is served from, not what a package contains. It essentially never holds an npm package hash, which is why npm identity is answered from OSV instead.

[https://urlhaus.abuse.ch/](https://urlhaus.abuse.ch/)

### abuse.ch ThreatFoxCC0-1.0 (public domain)

Command-and-control indicators: IPs, domains, and file hashes tied to active malware families.

**Freshness:** Refreshed daily.

**What it cannot tell you:** Indicator-based. A brand-new C2 that nobody has reported yet is not in it, and neither are we.

[https://threatfox.abuse.ch/](https://threatfox.abuse.ch/)

### OSV / OpenSSF malicious-packagesCC-BY-4.0 (advisory data)

Published malicious-package advisories (MAL- records and equivalent GHSA malware advisories). This is what makes a `malicious` verdict reachable for npm at all.

**Freshness:** Queried live per request, never a stale local copy.

**What it cannot tell you:** Advisories land AFTER a compromise is discovered, sometimes days after. A package published as malware an hour ago is not in it yet. Coverage is also version-scoped, so an unpinned name may be unanswerable.

[https://osv.dev/](https://osv.dev/)

### Lazaretto rule engineProprietary

Deterministic behavioral rules over the artifact itself: credential access, exfiltration, obfuscation, dynamic execution, persistence, install-time droppers, prompt injection aimed at an agent.

**Freshness:** Versioned; every change bumps `rules_version` and invalidates cached verdicts.

**What it cannot tell you:** Heuristics, so they cap at `flagged` and never produce `malicious` on their own. They read source text: a minified or packed bundle is reported as partially analyzed rather than silently skipped.

[/v1/rules](https://lazaretto.dev/v1/rules)

## Licences we hold indicators under

- `CC0-1.0`: 78,502 indicators
- `internal-corpus`: 16 indicators

The abuse.ch feeds are public domain, so crediting them is not a licence obligation. We do it because you deserve to know whose data is behind a verdict, and a source we would be reluctant to name would be a source we should not be using.

## What we do not cover

Stated as plainly as the coverage above, because a `clear` verdict being read as a clean bill of health is the one misunderstanding this product cannot afford:

- We do not execute anything. Behavior that only appears at run time, against a live C2, or on a specific OS, is outside what static analysis can see.
- We do not detect novel malware by reputation or machine learning. If no indicator matches and no rule fires, we say exactly that, and it is not a clean bill of health.
- Very large packages can exceed our size budget. When that happens the report is marked partial rather than returned as a confident `clear`.
- A minified or bundled artifact is only partly readable by source-level rules, and every report says so when it happens.
- Advisory feeds are retrospective. The window between a malicious release and its advisory is real, and nothing here closes it.

## How these sources behave in practice

Naming an upstream says where the data came from, not how much of it lands as noise on a package you meant to install. That is measured separately and published with the corpus attached, including the packages we flagged out of a list people install on purpose, and every attack sample of ours that goes undetected: [how often we flag a package people install on purpose](https://lazaretto.dev/benchmark).

## Check us

Live counts and freshness: [/v1/health](https://lazaretto.dev/v1/health) · rule catalog: [/v1/rules](https://lazaretto.dev/v1/rules) · our own noise numbers: [/benchmark](https://lazaretto.dev/benchmark) · mistakes we have corrected: [/corrections](https://lazaretto.dev/corrections)

---

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