Halcyon
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Field note · lookalike domains

Real-time scam intelligencefor crypto

Halcyon tracks phishing sites, wallet drainers, and scammer addresses, and publishes them as a blocklist that stays current. A free browser add-on for individuals. An API for teams.

Get the free add-on Request API access

Networks the blocklist is built to watch

  • Ethereum
  • Bitcoin
  • Solana
  • Tron
  • TON
  • Sui

How the data is made

One pipeline, from first sighting to the blocklist

Every product reads the same feed. Candidate sites and addresses come in around the clock, get verified, and ship to the blocklist.

01 · Detect

31M URLs scanned

Candidate sites and addresses are collected around the clock, from independent sources.

02 · Verify

412K scams identified

Each entry is checked before it is added. Automated checks first, a person when the call is not clear.

03 · Deliver

186K domains blocked

Verified entries ship to the API and the browser add-on from the same list.

For teams

Look up a domain or an address

One lookup, answered at the edge. Ask for a key, read the shape of the response, and wire it into the product your users already open.

  • Domain and URL checks, one at a time or in a batch
  • Address checks, one at a time or in a batch
  • Blocklist export for teams that run their own screen
Request API access

Example site check

$ curl "https://api.mmmmj.eu.cc/v1/site?url=https://swap-portal-fi.net" \
  -H "authorization: Bearer $HALCYON_KEY"

{
  "host": "swap-portal-fi.net",
  "status": "BLOCKED"
}

Sample response. Not a live call from this page.

This demo only recognizes the sample hosts in the feed above. It is not a live verdict.

Safe browsing

Wallets and add-ons

Check a link against the domain blocklist before a person opens it.

Monitoring

Security desks

Fold the blocklist into detection, tracing, and alerts you already run.

Review

Risk and compliance

Screen an address against known scammer addresses during review.

Field notes

Notes from the same pipeline

Short research from the feed behind the blocklist. Written for operators and for anyone who signs on a phone.

Black metal plates on graphite with a cut red thread

Where mobile phishing actually lands

Most of the losses we trace now start on a phone, inside a popup or a social ad, not on a desktop bookmark.

The lookalike domain is usually live for hours, not weeks. A blocklist only helps if it moves on that clock.

Dark laptop hinge with a cyan reflection on the screen

From an ad click to a seed request

The page after a malicious ad rarely asks for a signature first. It asks for a recovery phrase, dressed up as a restore.

Halcyon will not ask you for a seed phrase. No honest blocklist product needs one.

Teal fiber-optic strands ending in a frayed red burst

When the preview before you sign is a lie

A simulation preview can show a friendly balance change while the transaction underneath does something else.

The add-on is meant to flag that class of prompt before the approval leaves the phone.

Pricing

Start free. Add the API when a product needs the live list.

For individuals

Add-on

$0

The browser add-on for personal use. The same blocklist the API serves, with a lighter rate of checks.

  • Warnings on known phishing sites
  • Prompts before risky signatures
  • No wallet connection and no seed phrase
Get the free add-on
For small teams

Standard

from $890 / month

Live lookups for a single product. Priced by query volume.

  • Real-time domain and URL blocklist
  • Malicious address blocklist
  • REST lookup with standard limits
Request API access

Enterprise

Custom

For wallets, exchanges, and security platforms. Priced by scope and volume.

  • Bulk feed access
  • Attribution notes on drainer families
  • A named contact and a custom integration
Contact the desk

The same blocklist, in the browser. Free.

Halcyon warns you when a site or an address is on the list, before the page asks you to sign or to type a recovery phrase.

  • Safe browsing before the link opens
  • A prompt before risky signatures
  • No seed phrase, ever
Get the free add-on

Request

Tell us where to send it

The form stays on this device. Nothing is uploaded. If you want a person to reply, use your mail app and write to the desk.

Get the free add-on Email desk@mmmmj.eu.cc

Free browser add-on

Get it

Request Halcyon

No seed phrase. This form does not leave your device.