Specter-FlipperZero

_{The waveform is not a graphic. It is 128 columns of 13.56 MHz carrier that Specter recorded off a real polling reader at 8 ms per column, read back out of the screenshot beside it. Its duty measures 28% where the device's own counter printed 27%, and both numbers are on the banner.}

Sweep for the readers you can't see.

Project site  ·  Download  ·  Changelog

Specter turns your Flipper Zero into a pocket counter-surveillance bug-sweep for active 13.56 MHz NFC readers. It passively listens for the RF field that a powered-on reader is constantly emitting — a hidden card skimmer slipped into a payment terminal, a covert reader behind a door panel, a rogue logger taped under a desk — then tells you where it is, what kind of thing it is, whether the room is clean, and — left on watch — the moment one appears while you're away. It never transmits.

_{The readers are invisible. Specter makes them visible.}

_{As featured in
Help Net Security  ·  Cyber Security News}

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On the Flipper

_{A sweep, start to finish: quiet room → closing in → locked on → what it is → the room's verdict.}

The screens no single mode owns

_{The quiet states and the intro — the four modes below each carry their own capture, so these are the ones they do not. Every image in this README is a capture off a real device, taken over the Flipper's own RPC session by tools_screenshot.py. There is no mockup renderer in this project any more — a drawing of the UI is a second implementation of it, and it disagreed with the firmware while looking perfectly convincing (see 3.0.1).}

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The five modes

Specter is five tools around one sensor. Each answers a different question, so the right one depends on what you are actually trying to find out:

Mode	The question it answers	Use it when
Sweep	Where is it?	You suspect a device and want to pinpoint it by moving around
Fingerprint	What kind of thing is it?	You have found an emitter and want to know how it behaves
Site Survey	Is this room clean?	You want one verdict for a whole space, hands-free
Watch Mode	Did one appear while I was away?	You are leaving the Flipper somewhere to stand guard
Logbook	What did I find, and when?	You are writing it up, or comparing today with last week — filter by finding type

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Sweep — where is it?

What it does. A live EMF-style meter. Hold the Flipper flat and move it slowly over the thing you're checking — a card terminal, a door reader, the underside of an ATM lip, a parcel, a desk. The needle rides the field strength in real time.

What you see.

• The dial — needle = live reading, the small dot = peak-hold (the strongest spot you've touched, so you can compare positions).
• FIELD % — the same reading as a number, with a ▲ / ▼ trend arrow telling you whether the last half-second made things warmer or colder. When you're hunting, that arrow matters more than the number.
• PEAK % — the strongest reading since you armed, the number behind the peak-hold dot.
• The mark across the dial — where READER begins at your current sensitivity. Everything past it is what Specter will call a hit, so the dial answers "what counts?" instead of leaving you to guess.
• Bottom strip — until you've found your first reader it carries the two keys you can't discover by pressing things (LEFT=cal, hold OK=log); after that, your sensitivity and a live waveform. It flips to a black ● ACTIVE READER alarm bar with a proximity word the moment a carrier is detected.
• Proximity — FAINT → NEAR → CLOSE → STRONG → PEGGED. PEGGED means the meter is pegged: you're as close as this measurement can resolve.