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Case Study · CW-2026-0431 · DeFi yield / auto-trading bot

The ‘Expert Advisor’ Bot That Drained a Wallet Through One Approval: £71,500

A Leeds software contractor joined a DeFi community and connected his wallet to an automated ‘expert advisor’ bot run by Expert Advisories, promising 1.8% a day. The catch wasn’t a deposit — it was a single token approval.

MethodMalicious token approval (unlimited allowance)
Reported loss£71,500 (USDT + ETH)
Timeline~6 weeks
Recovered64% recovered
OutcomePartial recovery

How the scam unfolded

Through a Discord group he was invited to Expert Advisories, which claimed to run an automated cross-exchange arbitrage ‘expert advisor.’ A glossy ‘audit certificate’ and a dashboard of steady gains built trust. To ‘activate the bot,’ he connected his wallet and approved the protocol to spend his USDT — granting an unlimited allowance.

Where it went wrong

The dashboard gains were fake. When he tried to withdraw ‘profits,’ the bot demanded a ‘performance gas fee.’ Shortly after, the unlimited approval he’d signed was used to drain his USDT, and a follow-on transaction took his ETH. The ‘audit’ linked to a cloned page.

“I never sent them money — that’s what fooled me. I just clicked ‘approve.’ I didn’t realise one signature handed over everything.”— Tom, Leeds, UK

How the recovery worked

  1. 1
    Identified the approval. We pinpointed the exact unlimited-allowance transaction and the contract that exploited it.
  2. 2
    Revoked active permissions. We helped him revoke remaining approvals to stop further loss on his other tokens.
  3. 3
    Traced the drained funds. The USDT moved across a bridge, then to two exchanges; the ETH followed a separate path.
  4. 4
    Engaged the exchanges. Evidence packets went to both platforms; both held tranches that hadn’t yet been withdrawn.
  5. 5
    Recovered the held tranches. After compliance review, those tranches were returned — 64% of the reported loss.
Recovered for the client64%

Approval-based drains are quick, but this one was reported fast enough that two exchanges still held meaningful balances. The bridged remainder was not retrievable.

Warning signs to remember

  • Any dApp that needs an ‘unlimited’ token approval to ‘activate’ — set spending limits and revoke after use.
  • Guaranteed daily returns (‘1.8% a day’) — sustainable arbitrage doesn’t look like this.
  • An ‘audit certificate’ hosted on the project’s own site rather than the auditor’s.
  • Withdrawals gated behind a new ‘performance’ or ‘gas’ fee.
What you can learn
  • Connecting a wallet and approving a token are powerful actions — a single approval can authorise a full drain.
  • Use a revoke tool to review and cancel old approvals regularly.
  • Treat ‘expert advisor’ or ‘arbitrage’ bots promising fixed daily yields as red flags, not opportunities.

Think this has happened to you?

If you’ve lost crypto to an operator like this, the first hours matter. Our team will review your case and tell you honestly what can and can’t be recovered — at no upfront cost.

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Disclaimer: Cryptowledge provides digital-asset investigative and recovery-assistance services. Past case outcomes do not guarantee future recovery. Recovery is not possible in every case and depends on the specific circumstances, transaction path, and cooperation of third parties. Cryptowledge is not a law firm, financial advisor, or regulated financial institution and does not provide legal, tax, or investment advice. All consultations are confidential. © 2026 Cryptowledge. All rights reserved.