Extorsionware: Exploiting Smart Contract Vulnerabilities for Fun and Profit

Abstract: Smart Contracts (SCs) publicly deployed on blockchain have been shown to include multiple vulnerabilities, which can be maliciously exploited by users. In this paper, we present extorsionware, a novel attack exploiting the public nature of vulnerable SCs to gain control over the victim's SC assets. Thanks to the control gained over the SC, the attacker obliges the victim to pay a price to re-gain exclusive control of the SC.