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

Image Formats (Plinian Divider)

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

Document & Structured Data Formats (Plinian Divider)

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

Audio, Binary & Archive Formats (Plinian Divider)

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

Code & Config Formats (Plinian Divider)

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

How to Use

1. Open ST3GG in your browser
2. Go to the Agent tab
3. Upload any example file
4. Enable Exhaustive Mode for the most thorough analysis
5. Run the agent and watch it find the hidden data

Unicode & Text Tricks (Plinian Divider)

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.)

Network Protocol Steganography (Plinian Divider)

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

Image Format Tricks (Plinian Divider)

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)

Miscellaneous Techniques (Plinian Divider)

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)

More Unicode & Text Tricks (Plinian Divider)

File	Technique	What's Hidden
example_directional_override.txt	Bidi overrides (RLO/LRO)	Plinian divider in directional control chars with PDF cancellation
example_hangul_filler.txt	Hangul filler (U+3164)	Plinian divider in Korean invisible filler vs regular space
example_braille.txt	Braille patterns (U+2800)	Plinian divider bytes mapped to Braille Unicode block
example_math_alphanumeric.txt	Math bold (U+1D400)	Plinian divider in normal vs mathematical bold letter substitution
example_normalization.txt	NFC vs NFD	Plinian divider in Unicode normalization form choice per word
example_sentence_length.txt	Sentence word count	Plinian divider in odd (=1) vs even (=0) word count sentences
example_word_choice.txt	Synonym substitution	Plinian divider in synonym A (=0) vs synonym B (=1) selection
example_misspelling.txt	Typo patterns	Plinian divider in correct (=0) vs deliberately misspelled (=1) words

More Network Protocol Steganography (Plinian Divider)

File	Technique	What's Hidden
example_ttl_covert.pcap	IP TTL covert channel	Plinian divider bytes encoded directly in IP TTL field values
example_ipid_covert.pcap	IP ID field encoding	Plinian divider 2 bytes per packet in IP Identification field
example_tcp_window.pcap	TCP window size	Plinian divider 2 bytes per packet in TCP window size field
example_tcp_urgent.pcap	TCP urgent pointer	Plinian divider in TCP URG pointer with URG flag set
example_dns_txt.pcap	DNS TXT record	Plinian divider base64-encoded in DNS TXT response record
example_covert_timing.pcap	Covert timing channel	Plinian divider in inter-packet delays (10ms=0, 50ms=1)
example_multibase.txt	Multi-base encoding	Plinian divider in base16, base32, base64, and base85
example_morse.txt	Morse code	Plinian divider encoded in dot-dash Morse alphabet

Advanced Image Techniques (Plinian Divider)

File	Technique	What's Hidden
example_pvd.png	Pixel Value Differencing	Plinian divider in adjacent pixel pair difference parity
example_histogram_shift.png	Histogram shifting	Plinian divider via peak pixel value shifting (peak=0, peak+1=1)
example_lsb_4bit.png	LSB 4-bit per channel	Plinian divider using 4 lower bits per channel (high capacity)
example_lsb_msb_first.png	LSB MSB-first ordering	Plinian divider with reversed bit extraction order per byte
example_bmp_dib.bmp	BMP DIB header fields	Plinian divider in reserved header bytes + trailing data
example_gif_disposal.gif	GIF disposal method	Plinian divider in frame disposal flag bits
example_jpeg_app.jpg	JPEG APP segment	Plinian divider in custom APP14 segment (ST3GG identifier)
example_ycbcr.png	YCbCr color space	Plinian divider in Cb chrominance channel LSB after RGB conversion
example_png_chunks_custom.png	PNG custom chunks	Plinian divider in private stEg/sT3g ancillary PNG chunks

More Document & Archive Techniques (Plinian Divider)

File	Technique	What's Hidden
example_pdf_javascript.pdf	PDF JavaScript	Plinian divider base64 in OpenAction JavaScript
example_pdf_incremental.pdf	PDF incremental update	Plinian divider in appended incremental update annotation
example_pdf_forms.pdf	PDF form fields	Plinian divider in hidden form field default values
example_html_events.html	HTML event handlers	Plinian divider in onclick, onload, onmouseover attributes
example_xml_entities.xml	XML entity declarations	Plinian divider in DOCTYPE entity definitions + per-byte entities
example_nested.zip	Nested ZIP archive	Plinian divider in inner ZIP comment + secret.txt inside ZIP-in-ZIP
example_emoji_skin_tone.txt	Emoji skin tone selectors	Plinian divider in skin tone modifier choice (4 tones = 2 bits)
example_punycode.txt	Punycode/IDN domains	Plinian divider bytes encoded as internationalized domain names

Final Techniques (Plinian Divider)

File	Technique	What's Hidden
example_jpeg_restart.jpg	JPEG restart markers + COM	Plinian divider in RST marker indices + COM comment segment
example_matched_pairs.png	Matched pairs LSB	Plinian divider in pixel pair ordering (left>right=1, left<=right=0)
example_scanline_filter.png	PNG scanline filter abuse	Plinian divider in per-row filter byte choice (None=0, Sub=1)
example_qr_steg.txt	QR code data encoding	Plinian divider in QR data bit pattern + error correction analysis

Audio DSP Techniques (Plinian Divider)

File	Technique	What's Hidden
example_echo_hiding.wav	Echo hiding	Plinian divider in echo delay patterns (short=0, long=1)
example_phase_coding.wav	Phase coding	Plinian divider in DFT phase of frequency bins per segment
example_spread_spectrum.wav	Spread spectrum (DSSS)	Plinian divider spread via PN sequence at low amplitude
example_quantization_noise.wav	Quantization noise	Plinian divider in 2nd LSB of 16-bit audio samples

Image DSP Techniques (Plinian Divider)

File	Technique	What's Hidden
example_bpcs.png	BPCS	Plinian divider in complex 8x8 bit-plane blocks (complexity segmentation)
example_dct_manual.png	DCT coefficient	Plinian divider in mid-frequency DCT coefficients of 8x8 blocks
example_dft.png	DFT magnitude	Plinian divider in Fourier transform magnitude spectrum
example_dwt_haar.png	DWT Haar wavelet	Plinian divider in HH high-frequency wavelet subband
example_subsampling.png	Chroma subsampling	Plinian divider in 4:2:0 vs 4:4:4 chroma pattern per 2x2 block

Misc Techniques (Plinian Divider)

File	Technique	What's Hidden
example_self_extracting.sh	Self-extracting archive	Plinian divider in base64 tar.gz payload embedded in shell script
example_xattr.txt	Extended attributes	Plinian divider in user.st3gg.payload xattr (+ b64, hex, flag)
example_tls_cert.pem	TLS certificate fields	Plinian divider in CN, SAN, extension fields of certificate structure

Regenerating Files

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).