Blender.io OFAC mixer designation

Blender.io was the first Bitcoin mixer OFAC designated, named in May 2022 for laundering proceeds of a major heist.

TL;DR

TL;DR: OFAC designated the Bitcoin mixer Blender.io in May 2022, the first mixer it designated, for laundering proceeds tied to a large cryptocurrency heist. Any transaction with a designated mixer is a strict-liability violation.

What happened

Blender.io operated as a Bitcoin mixing service that obscured the trail of funds. OFAC designated it in May 2022, citing its role in laundering proceeds, including funds connected to a North Korean cyber heist. The designation placed Blender.io on the SDN List and blocked US persons from transacting with it.

The violation cited

Mixers are designated for facilitating money laundering at scale, and once designated they are blocked parties. Any transaction with them violates sanctions under strict liability, meaning intent is not required, with civil penalties starting at $356,000 per violation. The 50 Percent Rule also blocks entities 50% or more owned by a blocked person, which later extended to Blender.io's successor, Sinbad.io.

The lesson

The first mixer designation established the pattern enforcement still uses, and the same check applies to any successor. A screening check that inspects a counterparty address against 947 OFAC-listed crypto wallets in one call under 100 ms returns BLOCK for a designated mixer before funds move. Clean addresses return ALLOW. Payment rails such as x402, AP2, and ACP move money but do not screen, so the check must sit in front of the transfer, and tools such as agentmail provide that check.