Threat Level: green Handler on Duty: Johannes Ullrich

SANS ISC: CyberChef: BASE64/XOR Recipe - SANS Internet Storm Center SANS ISC InfoSec Forums


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CyberChef: BASE64/XOR Recipe

I often use commandline tools for malware analysis, like for the BASE64/XOR decoding I did in my last diary entry.

Of course, there are alternatives if you prefer to use a tool with a graphical user interface. Like the online tool CyberChef.

Here I'm illustrating how I use CyberChef to decode the obfuscated URL from last diary entry's sample:

First I drag-and-drop the "From BASE64" operation to the recipe:

Then I provide the obfuscated URL (IDc1O2ltbFs9KCc9JjZbPi5DNSZiNicqbC00ITQsI0YiXCItXjo4V2gqSlY=) as input:

Finally I drag-and-drop the "XOR" operation to the recipe, and provide the key (HCAKSBC2PIUVCB2PI3GILUHGCIUGUYO2F3UC2UY3FO23OUYCF32OYUDHOYGU32FVYUO23GF) as UTF8 text:

 

Didier Stevens
Senior handler
Microsoft MVP
blog.DidierStevens.com DidierStevensLabs.com

DidierStevens

289 Posts
ISC Handler

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