ST3GG Example Files

Pre-encoded steganography samples for testing the Agent tab's Exhaustive Mode and other decoder tools without having to encode files yourself.

All new examples (Plinian divider series) encode the secret message:

⊰•-•✧•-•-⦑/L\O/V\E/\P/L\I/N\Y/⦒-•-•✧•-•⊱

Original Examples

File	Technique	What's Hidden
`example_lsb_rgb.png`	LSB RGB 1-bit (STEG v3 header)	Text message embedded in pixel LSBs
`example_png_chunks.png`	PNG tEXt chunks	Secret messages in metadata chunks
`example_trailing_data.png`	Trailing data after IEND	Data appended after PNG end marker
`example_metadata.png`	PNG metadata (base64 + hex)	Encoded strings in Description/HexData fields
`example_zero_width.txt`	Zero-width Unicode	Invisible characters between visible text
`example_whitespace.txt`	Whitespace encoding	Hidden bits in trailing spaces/tabs
`example_invisible_ink.txt`	Unicode tag characters	Invisible ink using U+E0000 range
`example_audio_lsb.wav`	Audio LSB	Message in least significant bits of audio samples

File	Technique	What's Hidden
`example_lsb.bmp`	BMP LSB RGB	Plinian divider in pixel LSBs
`example_comment.gif`	GIF comment extension	Plinian divider in GIF comment block
`example_lsb.gif`	GIF palette index LSB	Plinian divider in palette index LSBs
`example_metadata.tiff`	TIFF metadata (base64)	Plinian divider in TIFF description tag
`example_lsb.tiff`	TIFF LSB RGB	Plinian divider in pixel LSBs
`example_lsb.ppm`	PPM (Portable Pixmap) LSB	Plinian divider in raw pixel LSBs
`example_lsb.pgm`	PGM (Portable Graymap) LSB	Plinian divider in grayscale LSBs
`example_hidden.svg`	SVG XML comments + attributes	Plinian divider in comments, data-attrs, metadata
`example_lsb.ico`	ICO LSB RGB	Plinian divider in icon pixel LSBs
`example_metadata.webp`	WebP EXIF metadata	Plinian divider in EXIF ImageDescription
`example_lsb.webp`	WebP lossless LSB	Plinian divider in pixel LSBs

File	Technique	What's Hidden
`example_hidden.html`	HTML comments + zero-width + hidden divs	Plinian divider in comments, meta tags, invisible elements, zero-width chars
`example_hidden.xml`	XML comments + CDATA + PIs	Plinian divider in processing instructions, CDATA, attributes
`example_hidden.json`	JSON metadata fields	Plinian divider in base64, hex, and direct Unicode fields
`example_whitespace.csv`	CSV whitespace encoding	Plinian divider in trailing spaces/tabs per row
`example_hidden.yaml`	YAML comments + byte table	Plinian divider in comments, base64, hex, and per-byte references
`example_hidden.pdf`	PDF metadata + streams + post-EOF	Plinian divider in XMP metadata, content streams, and after %%EOF
`example_hidden.rtf`	RTF hidden text groups	Plinian divider in \v hidden text, info fields, bookmarks
`example_hidden.md`	Markdown HTML comments + zero-width	Plinian divider in HTML comments, link references, zero-width chars

File	Technique	What's Hidden
`example_lsb.aiff`	AIFF audio LSB + annotation	Plinian divider in sample LSBs and ANNO chunk
`example_lsb.au`	AU (Sun/NeXT) audio LSB	Plinian divider in sample LSBs and header annotation
`example_hidden.zip`	ZIP archive comment + trailing	Plinian divider in archive comment and appended after ZIP
`example_hidden.tar`	TAR PAX extended headers	Plinian divider in pax header comment and custom STEG fields
`example_hidden.gz`	GZip extra field + comment	Plinian divider in FEXTRA and FCOMMENT header fields
`example_hidden.sqlite`	SQLite hidden table	Plinian divider in `_steg_payload` table (direct, base64, hex)
`example_hidden.hexdump`	Hex dump embedded bytes	Plinian divider embedded at offset 0x40 in raw byte data
`example_hidden.mid`	MIDI SysEx + text event	Plinian divider in SysEx message and MIDI text event
`example_hidden.pcap`	PCAP packet payloads	Plinian divider split across UDP packet payloads

File	Technique	What's Hidden
`example_hidden.py`	Python comments + zero-width docstring	Plinian divider in comments, hex byte table, zero-width docstring
`example_hidden.js`	JavaScript zero-width + comments	Plinian divider in zero-width chars between tokens, hex comments
`example_hidden.c`	C comments + byte array	Plinian divider in block comments and `_cal_data[]` array literal
`example_hidden.css`	CSS comments + pseudo-elements	Plinian divider in comments, `::after` content, zero-width chars
`example_hidden.ini`	INI comments + byte table	Plinian divider in comments and calibration byte entries
`example_hidden.sh`	Shell whitespace + comments	Plinian divider in trailing whitespace and script comments
`example_hidden.sql`	SQL comments + byte checksums	Plinian divider in comments and per-byte checksum lines
`example_hidden.tex`	LaTeX comments	Plinian divider in TeX comments, base64, and hex
`example_hidden.toml`	TOML comments	Plinian divider in TOML comments, base64, and hex

File	Technique	What's Hidden
`example_homoglyph.txt`	Cyrillic/Latin homoglyphs	Plinian divider in Cyrillic letter substitutions (а vs a, с vs c, etc.)
`example_variation_selector.txt`	Unicode variation selectors	Plinian divider in VS1 (U+FE01) presence/absence after letters
`example_combining_diacritics.txt`	Combining Grapheme Joiner	Plinian divider in invisible U+034F marks after letters
`example_confusable_whitespace.txt`	Unicode space variants	Plinian divider in en/em/thin space substitution (2 bits per space)
`example_emoji_substitution.txt`	Emoji pair encoding	Plinian divider in emoji choice (🌑=0 vs 🌚=1, etc.)

File	Technique	What's Hidden
`example_dns_tunnel.pcap`	DNS query name tunneling	Plinian divider base32-encoded in DNS query labels
`example_icmp_steg.pcap`	ICMP echo payload	Plinian divider in ICMP ping request payloads
`example_tcp_covert.pcap`	TCP covert channel	Plinian divider in TCP ISN + timestamp option fields
`example_http_headers.pcap`	HTTP header smuggling	Plinian divider in custom X- headers, cookies

File	Technique	What's Hidden
`example_polyglot.png.zip`	PNG+ZIP polyglot	Valid as both PNG image and ZIP archive with secret.txt
`example_filter_encoding.png`	PNG scanline filter types	Plinian divider in per-scanline filter byte choice (None=0, Sub=1)
`example_alpha_lsb.png`	Alpha channel LSB only	Plinian divider in transparency channel LSBs (RGB untouched)

File	Technique	What's Hidden
`example_key_ordering.json`	JSON key sort order	Plinian divider in object key ordering (alphabetical=0, reversed=1)
`example_capitalization.txt`	Letter case encoding	Plinian divider in word-initial capitalization (lower=0, upper=1)
`example_silence_interval.wav`	Audio silence timing	Plinian divider in silence gap durations (short=0, long=1)

If you want to modify the hidden messages or create new samples:

python3 examples/generate_examples.py

Requires Python 3 with Pillow (pip install Pillow).