Unverified contracts become "ATMs": SynapLogic was exploited 193 times by attackers for arbitrage, with a flash loan of 1 ETH minting 16,000 tokens

SynapLogic’s security vulnerability once again reminds us that unverified contracts are like an open door. According to the latest reports, CertiK detected 193 suspicious transactions related to unverified contracts of SynapLogic, with attackers executing efficient arbitrage through flash loans and repeated contract function calls. Although the individual token involved in this incident has a limited market cap, the exposed attack pattern is worth noting.

Attack Method Analysis

The core logic of this attack is not complicated, but its execution efficiency is high. Based on monitoring data, the attacker employed the following steps:

• Borrowed 1 ETH via a flash loan (no collateral needed, just repay within the same transaction)
• Used the borrowed ETH to call SynapLogic contract functions
• Repeatedly triggered contract logic to mint 16,000 SYP tokens
• Repaid the ETH before the transaction ended, completing the arbitrage loop
• Used multiple new addresses to disperse operations, reducing traceability risk

This “flash loan + contract vulnerability” combined attack is not unfamiliar in the DeFi space, but each successful attempt clearly indicates significant flaws in the project’s risk prevention measures.

Project Background and Risk Assessment

According to publicly available information, SYP is the token of the Sypool project, launched on September 21, 2021. However, market data shows this is a very small project:

This market cap means that even if the attacker minted 16,000 tokens, the actual value is quite limited. But the issue isn’t the amount; it’s the security of the contract itself—an unverified contract being so easily exploited indicates that the project team did not conduct thorough security audits before deployment.

Why 193 Transactions?

The reason the attacker could perform 193 operations reflects two issues:

Contract Design Flaws

Unverified contracts typically haven’t undergone checks by third-party security audit firms (such as CertiK, Halborn, etc.). These contracts often contain logical vulnerabilities, improper permission controls, reentrancy risks, and more.

Lack of Protective Mechanisms

Responsible projects usually implement protections like rate limiting, single-transaction caps, whitelists for callers, etc. SynapLogic clearly lacks these safeguards.

The Larger Picture of On-Chain Security

This incident is not isolated. According to recent monitoring by CertiK, on-chain security events are frequent—from the $282 million whale scam in early January, to various contract exploits, to mixer pools used for money laundering. The entire ecosystem’s risk prevention still needs strengthening. The existence of security firms like CertiK highlights a reality: unverified contracts and projects still exist in large numbers within Web3.

Lessons for Investors

The key lessons for investors are clear:

• Small-cap tokens do not mean low risk; in fact, they may carry higher risks due to lower attention and weaker protections
• Unverified contracts are like “products without certifications”; participation should be avoided
• Even if a project claims to be “secure,” verify whether there is an audit report from an authoritative institution
• Flash loans are innovative tools but also serve as weapons for attackers

Summary

SynapLogic’s experience is a typical case of contract vulnerability exploitation. Although 193 transactions are numerous, they fundamentally reflect the same issue: unverified contracts cannot safely hold user funds. The warning for the entire industry is that security audits are not optional but essential. Project teams need to complete formal security audits before launch, and investors should verify whether a project has been audited before participating. In the rapid development of Web3, security must always come first.