Listing hijacking is when an unauthorized seller starts offering your product on your own ASIN. They may be selling counterfeits, expired goods or grey-market imports. Either way, they typically undercut your price, take your Buy Box and damage your reviews. Catching it fast matters.

This guide is about detecting hijacking through data, not by accident.

TL;DR: Listing hijackers appear in your ASIN’s offers list. SP-API’s competitive pricing data lists every seller offering each ASIN. Tracking the offers list daily lets you spot a new unauthorized seller within hours instead of days. Brand-registered sellers can use Amazon’s enforcement tools (Project Zero, Brand Registry) once you have evidence. The detection is the bottleneck — enforcement is the easier part.

How hijackers appear in your data

SP-API’s Pricing endpoints expose the full offer list per ASIN — every seller currently offering that product, their price, fulfillment method and whether they hold the Buy Box.

For each of your ASINs, the offer list should typically only include:

• Your seller account.
• Authorized resellers (if you have any).
• Amazon retail (for vendor sellers).

Anyone else is a potential hijacker.

What to monitor

New sellers appearing

Daily diff between today’s offer list and yesterday’s. Any new seller that is not on your authorized list triggers an alert.

Buy Box loss patterns

If you suddenly lose the Buy Box on multiple ASINs and the new winner is the same unfamiliar seller across all of them, you likely have a coordinated hijacker.

Review velocity changes

Hijackers selling counterfeits or off-spec product often drive a spike in negative reviews — especially “not as described” or “inauthentic” feedback. Monitor review trends per ASIN.

Refund and return spikes

Same SKU, sudden return rate jump. Often the first sign customers received hijacker product instead of yours.

How to detect quickly with the data layer

The reliable detection workflow:

• Pull the offers list per ASIN per marketplace daily.
• Maintain a known-good seller list per ASIN (you and authorized resellers).
• Diff today’s offers against yesterday’s and against the allowlist.
• Alert on any unrecognized seller.
• Cross-reference with Buy Box ownership changes.

This takes minutes to set up if your data layer already has the offers data. Without one, it is a manual exercise nobody actually runs.

How to act on detection

Document the evidence

Take screenshots, save the offers list snapshot, capture pricing and fulfillment details. Amazon enforcement requires specific evidence.

Test purchase

Buy from the hijacker. If the product is counterfeit, off-spec or expired, you have direct evidence for IP enforcement.

Use Brand Registry tools

If you are brand-registered, use Brand Registry’s Report a Violation tool. It is the fastest path to listing-level enforcement.

File counterfeit complaints if applicable

For confirmed counterfeits, Amazon’s Project Zero (if you qualify) or standard counterfeit complaints get listings removed.

Cease and desist

For grey-market or unauthorized resellers (not counterfeits), legal counsel may pursue distribution channel claims.

The bottom line

Hijacking is a solved problem at the data level. The offers list is in SP-API. The detection logic is straightforward. Brands that lose money to hijackers usually do so because nobody is running the daily check.

DataDoe’s Amazon data layer exposes the competitive offers list per ASIN so AI tools can flag unauthorized sellers as soon as they appear.