PicoCTF Undo

Created on 2026-05-22

• Undo
• Multiple levels of encoding have been done to the plaintext
• Linux commands taught are base64, rev and tr

Steps

• 1. Open terminal
• 2. Connect using nc foggy-cliff.picoctf.net 56487
• 3. Decode the Base64 using echo KTZvNHFycnE4LWZhMDFnQHplMHNmYTRlRy1nazNnLXRhMWZlcmlyRShTR1BicHZj | base64 -d (correct answer to question is just base64 -d)
• 4. Reverse the text using echo )6o4qrrq8-fa01g@ze0sfa4eG-gk3g-ta1ferirE(SGPbpvc | rev (correct answer to question is just rev)
• 5. Swap the dashes for underscores using echo cvpbPGS(Eriref1at-g3kg-Ge4afs0ez@g10af-8qrrq4o6) | tr '-' '_' (correct answer to question is just tr '-' '_')
• 6. Swap the parentheses for braces using echo cvpbPGS(Eriref1at_g3kg_Ge4afs0ez@g10af_8qrrq4o6) | tr '()' '{}' (correct answer to question is just tr '()' '{}')
• 7. Do a ROT13 to letters only using echo cvpbPGS{Eriref1at_g3kg_Ge4afs0ez@g10af_8qrrq4o6} | tr 'A-Za-z' 'N-ZA-Mn-za-m' (correct answer to question is just tr 'A-Za-z' 'N-ZA-Mn-za-m')
• 8. Flag is picoCTF{Revers1ng_t3xt_Tr4nsf0rm@t10ns_8deed4b6}