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Crypto Drainer Kits

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Crypto drainer kits explained: approval phishing contracts, permit signatures, drainer-as-service economics and the end-to-end flow from lure to swept wallet. No private keys are stolen - the victim signs the theft themselves, one click at a time.

TL;DR - Victim signs the theft themselves - unlimited allowance survives the site leaving.

THE SIGNATURE ARITHMETIC

Wallet security rests on who holds keys; drainers move the objective to who holds valid approvals:

  • approve() - ERC-20 allowance grant: spender can move balance up to set amount, unlimited with uint256 max
  • setApprovalForAll() - ERC-721/1155 blanket grant over an entire NFT collection
  • EIP-2612 permit - off-chain signature authorizing allowance without on-chain approval tx - one message, no pending-approval visibility
  • increaseAllowance and variants - the same grant under different ABI surface

A signed unlimited approval is a blank check that survives long after the website is gone - revocation requires the victim to act.

KIT STRUCTURE (DRAINER-AS-A-SERVICE)

LayerFunctionRevenue split
Contract factoryDeploys drainer contract per campaign, often behind vanity addressesKit operator takes baseline %
Frontend / widgetConnect modal and signature prompts on compromised or hosted pages-
Lure layerAirdrop claim, mint, support portal, fake marketplace listingRecruiter share
SweeperAuto-forward stolen approvals to consolidation wallets, chain-hopping on the waySplit across operator + promoter

Published drainer-as-service splits have run in the 10-30% of stolen value range to the kit operator, remainder to whoever sourced the victim click.

EXECUTION FLOW

  • Target selection from wallet lists - NFT holders, DeFi power users, airdrop farmers (holders are profiled per chain activity)
  • Lure delivery - sponsored social posts, Discord DMs, compromised project accounts, SEO-poisoned "claim" pages
  • Connection - wallet session opened through WalletConnect or injected provider on the page
  • Signature sequence - first prompt framed as "verify ownership" (permit), second as "claim" (allowance), often disguised as gas payment
  • Sweep - approvals executed to attacker contract, funds routed through mixers or cross-chain bridges within minutes

WHY IT WORKS

Signature prompts are unintelligible to most holders: hex blobs, unfamiliar contract addresses, wallet UI that reads "unlimited" in six-point type. And the social layer outranks the technical one - a legitimate-looking project with an existing audience converts far better than cold infrastructure.

EXIT AND DEFENSE VIEW

  • Exit rails: mixer hops, bridge rotation, CEX deposit from layered addresses (off-ramp landscape)
  • Victim defense: revoke.cash style allowance checks, wallet spending-simulation warnings, hardware wallet transaction parsing
  • Chain forensics: approval events are permanent on-chain evidence - clustering follows the sweeper onward

Approvals revoked within the hour mostly stop the loss; approvals left standing for weeks are inventory waiting for collection.

★ MEMBER BONUS — FIELD CHEAT SHEET

Hit reply to unlock the sheet - takes five seconds.

Post drainer observations below - chain, lure class, approval type signed, and sweep-to-mixer timing.

— RELATED GUIDES —
 
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