Bash Bunny

What is a Bash Bunny?

The Bash Bunny is an advanced USB attack tool from Hak5 that looks like an ordinary USB stick. Unlike the simpler Rubber Ducky, it can simultaneously impersonate multiple devices: keyboard, network adapter, and USB storage. A physical switch on the device lets you preload up to two attack payloads and activate them instantly. Particularly dangerous: as a network adapter, it can trick Windows into automatically transmitting credentials – without the user noticing anything.

Attack Techniques

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NTLM Credential Harvest

The Bash Bunny poses as an Ethernet adapter. Windows automatically tries to authenticate on the network and sends the NTLM password hash – which the attacker intercepts.

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HID Injection (BadUSB)

Simultaneously or alternatively, it can act as a keyboard and inject commands – just like a Rubber Ducky, but with more control and combination payloads.

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Data Exfiltration

As USB storage, it can copy files, browser passwords, or SSH keys from the target machine – fully automatically upon insertion.

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Combination Attacks

The Bash Bunny's strength lies in combination: network adapter + keyboard simultaneously allows complex attacks that simpler devices cannot perform.

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Community Payloads

Hundreds of ready-made payloads are available on GitHub – from password dumps to backdoor installations. No programming knowledge required.

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Arming Mode

In the third switch position, the device enters development mode and appears as a normal drive – making it easy to upload new payloads.

Demo: NTLM Credential Harvest

Simulate how the Bash Bunny intercepts Windows credentials as a network adapter. Plug in the device and watch the attack unfold.

Target Computer

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No device Windows recognizes: USB Ethernet Adapter
Operating System: Windows 11 Pro
Not plugged in
Responder – Hash Capture

Why is this so dangerous?

Automatic Windows authentication: Windows automatically tries to authenticate with every new network adapter. This mechanism was designed for convenience, not security.

Hash = password substitute: A captured NTLM hash can be used directly for Pass-the-Hash attacks – without knowing the plaintext password.

No user interaction required: The attack runs fully automatically. The user needs to click nothing, confirm nothing.

How to protect yourself

1. Never plug in unknown USB devices: No foreign USB devices, even those that look like normal sticks.

2. Lock USB ports: Device control via Windows Group Policy or endpoint security software.

3. Disable NTLM (Enterprise): In modern Windows environments, NTLM can be disabled in favor of Kerberos.

4. Network segmentation: Stolen hashes are less valuable when the network is segmented and access is restricted.

5. Lock your computer: The attack requires physical access. Always lock when you leave your workstation.