How Does vfat.io Work?
vfat.io is a multi-chain yield aggregator that simplifies DeFi yield farming across 18+ blockchains. It uses a novel 'Sickle' smart contract wallet system that lets users enter, exit, compound, and rebalance yield positions in single transactions while maintaining self-custody. With approximately $32M in TVL, vfat automates complex farming strategies that would otherwise require multiple manual transactions. The Sickle contracts have been audited by Electisec and yAudit. However, as an aggregator, vfat introduces layered risk: users are exposed to both vfat's smart contracts and every underlying protocol their funds are deposited into.
TVL
$37M
Sector
Yield
Risk Grade
C+
Value Grade
D
Core Mechanisms
2.2.4
NovelYield aggregation with automated compounding, harvesting, and rebalancing via Sickle smart contract wallets
Sickle is a per-user smart contract wallet deployed on each chain that can execute complex multi-step yield strategies in single transactions. Novel self-custody aggregation pattern.
2.1.2
Performance fees on yield generated through automated strategies
Standard yield aggregator fee model taking a percentage of harvested/compounded rewards.
7.1.1
Multi-chain yield farming across 18+ EVM chains with strategy-specific reward optimization
Aggregates yield opportunities across Ethereum, Arbitrum, Base, Optimism, Polygon, and many other chains.
8.2.1
Multi-chain deployment with per-chain Sickle contract instances
Sickle contracts deployed independently on each chain. Cross-chain portfolio tracking but no cross-chain fund movement.
5.4.1
Multisig-controlled strategy deployment and parameter management
Protocol upgrades and strategy whitelisting controlled by multisig. Audited by yAudit (June 2024).
3.3.3
Auto-compounding of yield farming rewards back into positions
Standard auto-compounding pattern common in yield aggregators like Yearn and Beefy.
How the Pieces Interact
A vulnerability in the shared Sickle contract codebase would be exploitable across all 18+ chains simultaneously, multiplying the attack surface and potential losses by the number of deployments.
vfat deposits user funds into third-party protocols (DEXs, lending, farms). A hack or rug in any downstream protocol creates direct losses for vfat users with no protocol-level insurance or backstop.
Strategy contracts have broad permissions to move funds within Sickle wallets. A malicious or buggy strategy update could drain user positions across the protocol.
Multisig controls which strategies can interact with user Sickle wallets. Compromised multisig could whitelist malicious strategies to drain funds.
What Could Go Wrong
- vfat.io deploys Sickle smart contract wallets across 18+ chains, creating a massive multi-chain attack surface — a vulnerability in the shared Sickle contract would be exploitable on every chain simultaneously.
- As a yield aggregator, vfat.io has composability risk across all underlying protocols it deposits into. A hack in any downstream protocol (AMM, lending, farm) directly impacts vfat users.
- The Sickle contract wallet pattern gives the protocol significant control over user funds for automated operations like compounding and rebalancing, creating smart contract risk beyond standard approve-and-deposit patterns.
Cross-Chain Sickle Contract Exploit
TailTrigger: Critical vulnerability discovered in Sickle smart contract wallet codebase that is exploitable across all 18+ deployed chains
- 1.Attacker discovers vulnerability in Sickle contract wallet shared across all chains — Exploit deployed simultaneously on multiple chains to maximize extraction before detection
- 2.User funds drained from Sickle wallets across highest-TVL chains — Losses multiply across every chain where Sickle is deployed
- 3.Protocol team pauses strategy contracts on remaining chains — All user positions frozen pending investigation and fix
- 4.Users lose confidence in smart contract wallet pattern — Mass migration from vfat across all chains, TVL collapses to near zero
Risk Profile at a Glance
Overall: C+ (40/100)
Lower score = safer