Useful websites:

[zkp]

Thanks, some of them are quite handy. I'd suggest you might want to add CyberChef.

From the description of CyberChef:

CyberChef is a simple, intuitive web app for carrying out all manner of „cyber“ operations within a web browser. These operations include simple encoding like XOR or Base64, more complex encryption like AES, DES and Blowfish, creating binary and hexdumps, compression and decompression of data, calculating hashes and checksums, IPv6 and X.509 parsing, changing character encodings, and much more.

Some examples usages:

• Convert data from a hexdump, then decompress
• Decrypt and disassemble shellcode
• Perform AES decryption, extracting the IV from the beginning of the cipher stream

Source is available here and it can also be run locally: https://github.com/gchq/CyberChef