Document Steganography

Tip

AWS ํ•ดํ‚น ๋ฐฐ์šฐ๊ธฐ ๋ฐ ์—ฐ์Šตํ•˜๊ธฐ:HackTricks Training AWS Red Team Expert (ARTE)
GCP ํ•ดํ‚น ๋ฐฐ์šฐ๊ธฐ ๋ฐ ์—ฐ์Šตํ•˜๊ธฐ: HackTricks Training GCP Red Team Expert (GRTE) Azure ํ•ดํ‚น ๋ฐฐ์šฐ๊ธฐ ๋ฐ ์—ฐ์Šตํ•˜๊ธฐ: HackTricks Training Azure Red Team Expert (AzRTE)

HackTricks ์ง€์›ํ•˜๊ธฐ

๋ฌธ์„œ๋Š” ์ข…์ข… ๋‹จ์ˆœํ•œ ์ปจํ…Œ์ด๋„ˆ์ž…๋‹ˆ๋‹ค:

  • PDF (๋‚ด์žฅ๋œ ํŒŒ์ผ, ์ŠคํŠธ๋ฆผ)
  • Office OOXML (.docx/.xlsx/.pptx are ZIPs)
  • RTF / OLE ๊ตฌํ˜• ํ˜•์‹

PDF

Technique

PDF๋Š” ์˜ค๋ธŒ์ ํŠธ, ์ŠคํŠธ๋ฆผ, ์„ ํƒ์  ๋‚ด์žฅ ํŒŒ์ผ์„ ํฌํ•จํ•˜๋Š” ๊ตฌ์กฐํ™”๋œ ์ปจํ…Œ์ด๋„ˆ์ž…๋‹ˆ๋‹ค. CTFs์—์„œ๋Š” ์ข…์ข… ๋‹ค์Œ์„ ์ˆ˜ํ–‰ํ•ด์•ผ ํ•ฉ๋‹ˆ๋‹ค:

  • ๋‚ด์žฅ๋œ ์ฒจ๋ถ€ํŒŒ์ผ ์ถ”์ถœ
  • ์˜ค๋ธŒ์ ํŠธ ์ŠคํŠธ๋ฆผ์˜ ์••์ถ• ํ•ด์ œ/ํ‰ํƒ„ํ™”๋กœ ์ฝ˜ํ…์ธ ๋ฅผ ๊ฒ€์ƒ‰ํ•  ์ˆ˜ ์žˆ๊ฒŒ ํ•˜๊ธฐ
  • ์ˆจ๊ฒจ์ง„ ์˜ค๋ธŒ์ ํŠธ(JS, ๋‚ด์žฅ ์ด๋ฏธ์ง€, ์ด์ƒํ•œ ์ŠคํŠธ๋ฆผ) ์‹๋ณ„

๋น ๋ฅธ ์ ๊ฒ€

pdfinfo file.pdf
pdfdetach -list file.pdf
pdfdetach -saveall file.pdf
qpdf --qdf --object-streams=disable file.pdf out.pdf

๊ทธ๋Ÿฐ ๋‹ค์Œ out.pdf ๋‚ด๋ถ€์—์„œ ์˜์‹ฌ์Šค๋Ÿฌ์šด ๊ฐ์ฒด/๋ฌธ์ž์—ด์„ ๊ฒ€์ƒ‰ํ•˜์„ธ์š”.

Office OOXML

๊ธฐ๋ฒ•

OOXML์„ ZIP + XML ๊ด€๊ณ„ ๊ทธ๋ž˜ํ”„๋กœ ๊ฐ„์ฃผํ•˜์„ธ์š”; payloads๋Š” ์ข…์ข… media, relationships ๋˜๋Š” ์ด์ƒํ•œ custom parts์— ์ˆจ๊ฒจ์ ธ ์žˆ์Šต๋‹ˆ๋‹ค.

OOXML ํŒŒ์ผ์€ ZIP ์ปจํ…Œ์ด๋„ˆ์ž…๋‹ˆ๋‹ค. ์ฆ‰:

  • ๋ฌธ์„œ๋Š” XML๊ณผ assets์˜ ๋””๋ ‰ํ„ฐ๋ฆฌ ํŠธ๋ฆฌ์ž…๋‹ˆ๋‹ค.
  • _rels/ relationship files๋Š” ์™ธ๋ถ€ ๋ฆฌ์†Œ์Šค๋‚˜ ์ˆจ๊ฒจ์ง„ ํŒŒํŠธ๋ฅผ ๊ฐ€๋ฆฌํ‚ฌ ์ˆ˜ ์žˆ์Šต๋‹ˆ๋‹ค.
  • ๋‚ด์žฅ ๋ฐ์ดํ„ฐ๋Š” ํ”ํžˆ word/media/, custom XML parts ๋˜๋Š” ๋น„์ •์ƒ์ ์ธ relationships์— ์กด์žฌํ•ฉ๋‹ˆ๋‹ค.

๋น ๋ฅธ ์ ๊ฒ€

7z l file.docx
7z x file.docx -oout

๋‹ค์Œ ํ•ญ๋ชฉ์„ ๊ฒ€์‚ฌํ•˜์„ธ์š”:

  • word/document.xml
  • word/_rels/์—์„œ ์™ธ๋ถ€ ๊ด€๊ณ„๋ฅผ ํ™•์ธํ•˜์„ธ์š”
  • ์ž„๋ฒ ๋””๋“œ ๋ฏธ๋””์–ด: word/media/

Tip

AWS ํ•ดํ‚น ๋ฐฐ์šฐ๊ธฐ ๋ฐ ์—ฐ์Šตํ•˜๊ธฐ:HackTricks Training AWS Red Team Expert (ARTE)
GCP ํ•ดํ‚น ๋ฐฐ์šฐ๊ธฐ ๋ฐ ์—ฐ์Šตํ•˜๊ธฐ: HackTricks Training GCP Red Team Expert (GRTE) Azure ํ•ดํ‚น ๋ฐฐ์šฐ๊ธฐ ๋ฐ ์—ฐ์Šตํ•˜๊ธฐ: HackTricks Training Azure Red Team Expert (AzRTE)

HackTricks ์ง€์›ํ•˜๊ธฐ