Wrench Attack

What Is a Wrench Attack?

A wrench attack, also known as a $5 wrench attack, refers to any physical assault or threat designed to force cryptocurrency holders to reveal their private keys or transfer funds. The term originates from a satirical XKCD webcomic illustrating how an attacker could threaten someone with a wrench to obtain their password.

Whether executed as home invasions, kidnappings, or robberies, these crimes force immediate access to cryptocurrency holdings. Unlike cybercrime, wrench attacks exploit human vulnerabilities through physical violence rather than targeting digital infrastructure. 

How Do Wrench Attacks Work?

Wrench attacks are rarely random. They typically involve a planning phase where criminals identify and research their targets.

• Target Identification: Attackers often find their victims online. Individuals who publicly discuss their crypto wealth on social media, in forums, or at industry events become attractive targets. This online footprint can provide criminals with enough information to locate a victim in the real world.
• Methods of Attack: Once a target is identified, the attack can take several forms, including home invasions, kidnappings, or street robberies. In numerous real-world cases, victims have been held at gunpoint, assaulted, and forced to unlock their phones or hardware wallets to transfer funds on the spot.
• The Goal: The attacker’s objective is immediate access. They aim to bypass all digital security measures by compelling the owner to cooperate. This can mean forcing a transaction, or stealing the seed phrase, which gives the attacker complete control over the victim’s wallet.

Mitigating Wrench Attacks

In the context of defending against wrench attacks, good operational security (OpSec) centers around generally maintaining a low profile and avoiding public discussions about cryptocurrency holdings, particularly online. Good OpSec makes it difficult for potential attackers to identify a target in the first place. General security measures, such as securing one’s home should of course be part of any physical defense strategy.

Certain wallet technologies can also mitigate the potential losses from such attacks, or even prevent them. Features like plausible deniability, often found in hardware wallets, allow for the creation of hidden decoy wallets to protect an owner’s main holdings under duress. Furthermore, multi-signature (multisig) wallets provide robust protection by requiring two or more private keys, stored in geographically separate locations, to authorize a transaction. This setup makes it logistically impossible for an attacker to force a complete transfer by coercing a single individual.