A Beginner’s Guide to CyberChef: Cooking Up Data Transformations

CyberChef, often called the “Cyber Swiss Army Knife,” is one of the most versatile tools in a security analyst’s kitchen. Whether you’re dealing with encoded data, timestamps, or suspicious-looking strings, CyberChef helps you break it down and uncover hidden meaning.

In this post, we’ll walk through the thought process when using CyberChef, explore its most useful operation categories, and try a few examples to get you comfortable with your first “cook.”

The Four-Step Thought Process

Before diving in, it’s important to approach CyberChef with a structured mindset. Here are the four key steps:

1. Define Your Objective

Ask yourself: “What do I want to accomplish?”
Setting a clear goal provides direction and focus. For example, if you find a gibberish string during an investigation, your objective might be:

“I want to know if this string contains a hidden message.”

2. Input the Data

Paste or upload your data into CyberChef’s input area. This could be a suspicious string, an encoded file, or even a log extract.

3. Choose Operations

This is where the magic happens. You select transformations or “operations” to apply to your data. For instance, if you suspect your gibberish string is encoded, you might try:

• Base64 / Base85 / Base58 decoding

• ROT13 or ROT47 transformations

• URL decoding

Choosing the right operation may take trial and error, but CyberChef makes it easy to experiment.

4. Check the Output

Finally, verify if the result matches your objective. Ask: “Did I get what I expected?”
If yes, you’re done. If not, go back and try a different approach—just like adjusting a recipe in a real kitchen.

Key CyberChef Operation Categories

CyberChef is packed with hundreds of operations, but you don’t need them all to get started. Let’s look at some of the most commonly used categories.

🔎 Extractors

These operations pull out useful data from raw input.

• Extract IP addresses → Finds all IPv4 and IPv6 addresses.

• Extract URLs → Pulls out valid links from text.

• Extract email addresses → Captures anything in the format user@domain.com.

Great for when you’re sifting through logs, phishing emails, or suspicious text dumps.

⏱ Date and Time

Work with UNIX timestamps and human-readable time formats.

• From UNIX Timestamp → Converts 1725654622 into a readable date.

• To UNIX Timestamp → Converts Fri Sep 6 20:30:22 +04 2024 into 1725654622.

This is invaluable when correlating logs or investigating timelines in incidents.

🔐 Data Formats (Encoding & Decoding)

Some of the most commonly used CyberChef operations fall under this category:

• From Base64 → Converts V2VsY29tZSB0byB0cnloYWNrbWUh into Welcome to tryhackme!.

• From Base85 / Base58 / Base62 → Variations of base encoding, often used in malware or obfuscation.

• URL Decode → Converts %3A%2F%2F into ://.

Manual Example: Base64 Encoding “THM”

1. Convert letters into binary:

   • T = 01010100, H = 01001000, M = 01001101 → Combined: 010101000100100001001101

2. Split into 6-bit chunks → 010101 000100 100001 001101

3. Convert to decimal → 21, 4, 33, 13

4. Map to Base64 table → V, E, h, N

Result: “THM” = VEhN in Base64.

Doing this manually shows how base encodings work under the hood—but in CyberChef, this is a one-click operation.

Practical Exercise

To practice, download a provided file (like in TryHackMe’s CyberChef Basics room) and load it into CyberChef. Try using:

• Extractors → Pull out IPs, emails, or URLs.

• Date/Time conversions → Decode timestamps.

• Base operations → Decode encoded strings.

This hands-on “cooking” will help solidify your understanding.

Wrapping Up

CyberChef is more than just a decoder—it’s a visual playground for data manipulation. By following a structured four-step process, you can:

• Define clear objectives

• Input your data

• Apply transformations

• Verify your results

From simple Base64 decoding to extracting hidden IPs or converting timestamps, CyberChef empowers analysts to uncover insights quickly and effectively.

And remember: every great analyst starts with their first cook. So, fire up CyberChef, experiment with recipes, and keep sharpening your cyber intuition.