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Lead in: Phalcon's Hack Blocking Saga

April 23, 2024

Since BlockSec's debut in 2021, we have long maintained that code auditing alone cannot solve all Web3 security issues. Therefore, we have been investing in exploring new paradigms for Web3 security. Thus we created Phalcon, the world's first crypto hack-blocking system.

Before the launch of Phalcon, the system had been running internally for 2 years, successfully blocking over 20 hacks, and rescuing more than 20 million USD worth of assets, including $3.8M for Saddle Finance, $2.4M for Platypus, $5M for ParaSpace, and more.

In this series of articles, we will present representative stories of our system Phalcon. In sharing these cases, we aim to do more than validate the effectiveness of our system. We also want to demonstrate the transformative effect of proactive defense measures.

In the face of threats, we are not powerless. Together, we can usher in a new era of Web3 security.

Breaking Down: A Comprehensive Overview

About Phalcon

Phalcon is a security platform developed by BlockSec to monitor and block hacks. The system detects suspicious transactions, instantly alerts users, and takes automated actions in response.

Use cases of Phalcon
Use cases of Phalcon

Phalcon is a SaaS platform where users can directly log in through our official website to view different pricing plans and features, and subscribe immediately (supporting both credit card and crypto payments). For any questions, feel free to book a demo with our security experts who will address your concerns.

Support Tool: Phalcon Explorer

Phalcon Explorer is a support tool for the Phalcon platform. This powerful transaction explorer is designed for the DeFi community. It provides comprehensive data on call flows, balance changes, and transaction fund flows, as well as supports transaction simulation. This helps developers, security researchers, and traders to more intuitively understand transactions.

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Newsletter - April 2026
Security Insights

Newsletter - April 2026

In April 2026, the DeFi ecosystem experienced three major security incidents. KelpDAO lost ~$290M due to an insecure 1-of-1 DVN bridge configuration exploited via RPC infrastructure compromise, Drift Protocol suffered ~$285M from a multisig governance takeover leveraging Solana's durable nonce mechanism, and Rhea Finance incurred ~$18.4M following a business logic flaw in its margin-trading module that allowed circular swap path manipulatio

~$7.04M Lost: GiddyDefi, Volo Vault & More | BlockSec Weekly
Security Insights

~$7.04M Lost: GiddyDefi, Volo Vault & More | BlockSec Weekly

This BlockSec weekly security report covers eight attack incidents detected between April 20 and April 26, 2026, across Ethereum, Avalanche, Sui, Base, HyperLiquid, and MegaETH, with total estimated losses of approximately $7.04M. The highlighted incident is the $1.3M GiddyDefi exploit, where the attacker did not break any cryptography or use a flash loan but simply replayed an existing on-chain EIP-712 signature with the unsigned `aggregator` and `fromToken` fields swapped out for a malicious contract, demonstrating how partial signature coverage turns any historical signature into a generic permit. Other incidents include a $3.5M Volo Vault operator key compromise on Sui, a $1.5M Purrlend privileged-role takeover, a $413K SingularityFinance oracle misconfiguration, a $142.7K Scallop cross-pool index injection, a $72.35K Kipseli Router decimal mismatch, a $50.7K REVLoans (Juicebox) accounting pollution, and a $64K Custom Rebalancer arbitrary-call exploit.

Weekly Web3 Security Incident Roundup | Apr 13 – Apr 19, 2026
Security Insights

Weekly Web3 Security Incident Roundup | Apr 13 – Apr 19, 2026

This BlockSec weekly security report covers four attack incidents detected between April 13 and April 19, 2026, across multiple chains such as Ethereum, Unichain, Arbitrum, and NEAR, with total estimated losses of approximately $310M. The highlighted incident is the $290M KelpDAO rsETH bridge exploit, where an attacker poisoned the RPC infrastructure of the sole LayerZero DVN to fabricate a cross-chain message, triggering a cascading WETH freeze across five chains and an Arbitrum Security Council forced state transition that raises questions about the actual trust boundaries of decentralized systems. Other incidents include a $242K MMR proof forgery on Hyperbridge, a $1.5M signed integer abuse on Dango, and an $18.4M circular swap path exploit on Rhea Finance's Burrowland protocol.