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/⦒-•-•✧•-•⊱
File
Technique
What's Hidden
example_lsb_rgb.pngLSB RGB 1-bit (STEG v3 header)
Text message embedded in pixel LSBs
example_png_chunks.pngPNG tEXt chunks
Secret messages in metadata chunks
example_trailing_data.pngTrailing data after IEND
Data appended after PNG end marker
example_metadata.pngPNG metadata (base64 + hex)
Encoded strings in Description/HexData fields
example_zero_width.txtZero-width Unicode
Invisible characters between visible text
example_whitespace.txtWhitespace encoding
Hidden bits in trailing spaces/tabs
example_invisible_ink.txtUnicode tag characters
Invisible ink using U+E0000 range
example_audio_lsb.wavAudio LSB
Message in least significant bits of audio samples
Image Formats (Plinian Divider)
File
Technique
What's Hidden
example_lsb.bmpBMP LSB RGB
Plinian divider in pixel LSBs
example_comment.gifGIF comment extension
Plinian divider in GIF comment block
example_lsb.gifGIF palette index LSB
Plinian divider in palette index LSBs
example_metadata.tiffTIFF metadata (base64)
Plinian divider in TIFF description tag
example_lsb.tiffTIFF LSB RGB
Plinian divider in pixel LSBs
example_lsb.ppmPPM (Portable Pixmap) LSB
Plinian divider in raw pixel LSBs
example_lsb.pgmPGM (Portable Graymap) LSB
Plinian divider in grayscale LSBs
example_hidden.svgSVG XML comments + attributes
Plinian divider in comments, data-attrs, metadata
example_lsb.icoICO LSB RGB
Plinian divider in icon pixel LSBs
example_metadata.webpWebP EXIF metadata
Plinian divider in EXIF ImageDescription
example_lsb.webpWebP lossless LSB
Plinian divider in pixel LSBs
Document & Structured Data Formats (Plinian Divider)
File
Technique
What's Hidden
example_hidden.htmlHTML comments + zero-width + hidden divs
Plinian divider in comments, meta tags, invisible elements, zero-width chars
example_hidden.xmlXML comments + CDATA + PIs
Plinian divider in processing instructions, CDATA, attributes
example_hidden.jsonJSON metadata fields
Plinian divider in base64, hex, and direct Unicode fields
example_whitespace.csvCSV whitespace encoding
Plinian divider in trailing spaces/tabs per row
example_hidden.yamlYAML comments + byte table
Plinian divider in comments, base64, hex, and per-byte references
example_hidden.pdfPDF metadata + streams + post-EOF
Plinian divider in XMP metadata, content streams, and after %%EOF
example_hidden.rtfRTF hidden text groups
Plinian divider in \v hidden text, info fields, bookmarks
example_hidden.mdMarkdown 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.aiffAIFF audio LSB + annotation
Plinian divider in sample LSBs and ANNO chunk
example_lsb.auAU (Sun/NeXT) audio LSB
Plinian divider in sample LSBs and header annotation
example_hidden.zipZIP archive comment + trailing
Plinian divider in archive comment and appended after ZIP
example_hidden.tarTAR PAX extended headers
Plinian divider in pax header comment and custom STEG fields
example_hidden.gzGZip extra field + comment
Plinian divider in FEXTRA and FCOMMENT header fields
example_hidden.sqliteSQLite hidden table
Plinian divider in _steg_payload table (direct, base64, hex)
example_hidden.hexdumpHex dump embedded bytes
Plinian divider embedded at offset 0x40 in raw byte data
example_hidden.midMIDI SysEx + text event
Plinian divider in SysEx message and MIDI text event
example_hidden.pcapPCAP packet payloads
Plinian divider split across UDP packet payloads
Code & Config Formats (Plinian Divider)
File
Technique
What's Hidden
example_hidden.pyPython comments + zero-width docstring
Plinian divider in comments, hex byte table, zero-width docstring
example_hidden.jsJavaScript zero-width + comments
Plinian divider in zero-width chars between tokens, hex comments
example_hidden.cC comments + byte array
Plinian divider in block comments and _cal_data[] array literal
example_hidden.cssCSS comments + pseudo-elements
Plinian divider in comments, ::after content, zero-width chars
example_hidden.iniINI comments + byte table
Plinian divider in comments and calibration byte entries
example_hidden.shShell whitespace + comments
Plinian divider in trailing whitespace and script comments
example_hidden.sqlSQL comments + byte checksums
Plinian divider in comments and per-byte checksum lines
example_hidden.texLaTeX comments
Plinian divider in TeX comments, base64, and hex
example_hidden.tomlTOML comments
Plinian divider in TOML comments, base64, and hex
Open ST3GG in your browser
Go to the Agent tab
Upload any example file
Enable Exhaustive Mode for the most thorough analysis
Run the agent and watch it find the hidden data
Unicode & Text Tricks (Plinian Divider)
File
Technique
What's Hidden
example_homoglyph.txtCyrillic/Latin homoglyphs
Plinian divider in Cyrillic letter substitutions (а vs a, с vs c, etc.)
example_variation_selector.txtUnicode variation selectors
Plinian divider in VS1 (U+FE01) presence/absence after letters
example_combining_diacritics.txtCombining Grapheme Joiner
Plinian divider in invisible U+034F marks after letters
example_confusable_whitespace.txtUnicode space variants
Plinian divider in en/em/thin space substitution (2 bits per space)
example_emoji_substitution.txtEmoji pair encoding
Plinian divider in emoji choice (🌑=0 vs 🌚=1, etc.)
Network Protocol Steganography (Plinian Divider)
File
Technique
What's Hidden
example_dns_tunnel.pcapDNS query name tunneling
Plinian divider base32-encoded in DNS query labels
example_icmp_steg.pcapICMP echo payload
Plinian divider in ICMP ping request payloads
example_tcp_covert.pcapTCP covert channel
Plinian divider in TCP ISN + timestamp option fields
example_http_headers.pcapHTTP header smuggling
Plinian divider in custom X- headers, cookies
Image Format Tricks (Plinian Divider)
File
Technique
What's Hidden
example_polyglot.png.zipPNG+ZIP polyglot
Valid as both PNG image and ZIP archive with secret.txt
example_filter_encoding.pngPNG scanline filter types
Plinian divider in per-scanline filter byte choice (None=0, Sub=1)
example_alpha_lsb.pngAlpha channel LSB only
Plinian divider in transparency channel LSBs (RGB untouched)
Miscellaneous Techniques (Plinian Divider)
File
Technique
What's Hidden
example_key_ordering.jsonJSON key sort order
Plinian divider in object key ordering (alphabetical=0, reversed=1)
example_capitalization.txtLetter case encoding
Plinian divider in word-initial capitalization (lower=0, upper=1)
example_silence_interval.wavAudio 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.txtBidi overrides (RLO/LRO)
Plinian divider in directional control chars with PDF cancellation
example_hangul_filler.txtHangul filler (U+3164)
Plinian divider in Korean invisible filler vs regular space
example_braille.txtBraille patterns (U+2800)
Plinian divider bytes mapped to Braille Unicode block
example_math_alphanumeric.txtMath bold (U+1D400)
Plinian divider in normal vs mathematical bold letter substitution
example_normalization.txtNFC vs NFD
Plinian divider in Unicode normalization form choice per word
example_sentence_length.txtSentence word count
Plinian divider in odd (=1) vs even (=0) word count sentences
example_word_choice.txtSynonym substitution
Plinian divider in synonym A (=0) vs synonym B (=1) selection
example_misspelling.txtTypo 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.pcapIP TTL covert channel
Plinian divider bytes encoded directly in IP TTL field values
example_ipid_covert.pcapIP ID field encoding
Plinian divider 2 bytes per packet in IP Identification field
example_tcp_window.pcapTCP window size
Plinian divider 2 bytes per packet in TCP window size field
example_tcp_urgent.pcapTCP urgent pointer
Plinian divider in TCP URG pointer with URG flag set
example_dns_txt.pcapDNS TXT record
Plinian divider base64-encoded in DNS TXT response record
example_covert_timing.pcapCovert timing channel
Plinian divider in inter-packet delays (10ms=0, 50ms=1)
example_multibase.txtMulti-base encoding
Plinian divider in base16, base32, base64, and base85
example_morse.txtMorse code
Plinian divider encoded in dot-dash Morse alphabet
Advanced Image Techniques (Plinian Divider)
File
Technique
What's Hidden
example_pvd.pngPixel Value Differencing
Plinian divider in adjacent pixel pair difference parity
example_histogram_shift.pngHistogram shifting
Plinian divider via peak pixel value shifting (peak=0, peak+1=1)
example_lsb_4bit.pngLSB 4-bit per channel
Plinian divider using 4 lower bits per channel (high capacity)
example_lsb_msb_first.pngLSB MSB-first ordering
Plinian divider with reversed bit extraction order per byte
example_bmp_dib.bmpBMP DIB header fields
Plinian divider in reserved header bytes + trailing data
example_gif_disposal.gifGIF disposal method
Plinian divider in frame disposal flag bits
example_jpeg_app.jpgJPEG APP segment
Plinian divider in custom APP14 segment (ST3GG identifier)
example_ycbcr.pngYCbCr color space
Plinian divider in Cb chrominance channel LSB after RGB conversion
example_png_chunks_custom.pngPNG 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.pdfPDF JavaScript
Plinian divider base64 in OpenAction JavaScript
example_pdf_incremental.pdfPDF incremental update
Plinian divider in appended incremental update annotation
example_pdf_forms.pdfPDF form fields
Plinian divider in hidden form field default values
example_html_events.htmlHTML event handlers
Plinian divider in onclick, onload, onmouseover attributes
example_xml_entities.xmlXML entity declarations
Plinian divider in DOCTYPE entity definitions + per-byte entities
example_nested.zipNested ZIP archive
Plinian divider in inner ZIP comment + secret.txt inside ZIP-in-ZIP
example_emoji_skin_tone.txtEmoji skin tone selectors
Plinian divider in skin tone modifier choice (4 tones = 2 bits)
example_punycode.txtPunycode/IDN domains
Plinian divider bytes encoded as internationalized domain names
Final Techniques (Plinian Divider)
File
Technique
What's Hidden
example_jpeg_restart.jpgJPEG restart markers + COM
Plinian divider in RST marker indices + COM comment segment
example_matched_pairs.pngMatched pairs LSB
Plinian divider in pixel pair ordering (left>right=1, left<=right=0)
example_scanline_filter.pngPNG scanline filter abuse
Plinian divider in per-row filter byte choice (None=0, Sub=1)
example_qr_steg.txtQR 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.wavEcho hiding
Plinian divider in echo delay patterns (short=0, long=1)
example_phase_coding.wavPhase coding
Plinian divider in DFT phase of frequency bins per segment
example_spread_spectrum.wavSpread spectrum (DSSS)
Plinian divider spread via PN sequence at low amplitude
example_quantization_noise.wavQuantization noise
Plinian divider in 2nd LSB of 16-bit audio samples
Image DSP Techniques (Plinian Divider)
File
Technique
What's Hidden
example_bpcs.pngBPCS
Plinian divider in complex 8x8 bit-plane blocks (complexity segmentation)
example_dct_manual.pngDCT coefficient
Plinian divider in mid-frequency DCT coefficients of 8x8 blocks
example_dft.pngDFT magnitude
Plinian divider in Fourier transform magnitude spectrum
example_dwt_haar.pngDWT Haar wavelet
Plinian divider in HH high-frequency wavelet subband
example_subsampling.pngChroma 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.shSelf-extracting archive
Plinian divider in base64 tar.gz payload embedded in shell script
example_xattr.txtExtended attributes
Plinian divider in user.st3gg.payload xattr (+ b64, hex, flag)
example_tls_cert.pemTLS certificate fields
Plinian divider in CN, SAN, extension fields of certificate structure
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).