Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c54fd1b8cf103c0…

MALICIOUS

PDF

750.2 KB Created: 2008-07-17 23:28:44 +08:00 Authoring application: Acrobat PDFMaker 7.0 for Word (via Acrobat Distiller 7.0 (Windows)) First seen: 2013-02-09
MD5: 81bc3eea1c644d109cebe191257c7efe SHA-1: 44953b48ff48dc97bda13de7f7e837db1a78752e SHA-256: 3c54fd1b8cf103c003c69eb43a9b623ad3e3bfb923f5d6c3313d4da03cea73c9
268 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, and PDF_EVAL. The critical POLYGLOT_CHILD_PDF_STATIC_TRIAGE finding suggests a secondary embedded PDF with similar suspicious static findings. The extracted JavaScript stream (stream_039_off000ba238.js) is the primary indicator of malicious activity, likely responsible for downloading and executing a second-stage payload. The confidence is high due to the critical heuristic findings and the presence of executable script content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9791

Heuristics 9

  • Obfuscated Pidief-style JavaScript loader (stage not decoded) high CVE related PDF_PIDIEF_OBFUSCATED_VERSION_GATED_LOADER
    PDF JavaScript carries a large opaque encoded stage (a large numeric character-code array feeding an auto-run script) that is built to be decoded and eval'd, but no exact Adobe Reader CVE could be attributed because the encoding scheme resisted full static decoding. This is the structural fingerprint of the Pidief / multi-CVE exploit-kit loader family — a version-gated obfuscated JavaScript stage with no benign use. Flagged suspicious on its own; an ML/AV signal or a recovered heap-spray pushes it to malicious.
  • Secondary embedded PDF body has suspicious static findings critical POLYGLOT_CHILD_PDF_STATIC_TRIAGE
    A valid PDF body was found at a nonzero offset inside another container and its carved contents matched PDF exploit or lure heuristics. This catches polyglots where the top-level magic routes to ZIP/OLE while a PDF reader or downstream parser opens the hidden PDF payload.
  • JavaScript action low 2 related findings PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
    Matched line in script
    eval(cc);
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://www.w3.org/1999/02/22-rdf-syntax-ns# In PDF document text
    • http://ns.adobe.com/iX/1.0/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/pdfx/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/photoshop/1.0/In PDF document text

Extracted artifacts 22

Files carved from inside the sample during analysis.

FilenameKindSourceSize
3.jpg pdf-embedded-file PDF EmbeddedFile object 31 at offset 0x2303 542 bytes
SHA-256: c30ff3efd01a63725d5ed9ca0f6998d438c910c132f65d14b3771519f05b1aaa
stream_041_off000ba238.js decompressed-pdf-stream PDF FlateDecoded stream at offset 0xBA238 3433 bytes
SHA-256: 98e3c3ca0476ffedc3c2fffc3d2bff11646ce68d12d65706966657d0d9c107a5
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
icc_00_off00034faf.icc pdf-icc-profile PDF ICC profile at offset 0x34FAF 1320 bytes
SHA-256: eb03db58ff1f226c83103a11f30b5520f9b68a7ced67daa78992723e3ea0411d
font_00_sfnt_off0004aed7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x4AED7 3864 bytes
SHA-256: 194f92554034e60257983fd76c25151d6467c7ccb45ac5cd515d30b204d2726c
font_01_sfnt_off0004bbcb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x4BBCB 9544 bytes
SHA-256: 86a191427cdeb783c11e7a9c40550fd03af1c89a97ba2a9338536d55595ec542
font_02_sfnt_off0004d8af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x4D8AF 16936 bytes
SHA-256: 6c5af6f6b1048f2e36c644cc4a05628c6f098238f0c539d8a50a9ec1c4cfbe3b
font_03_sfnt_off00050e29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x50E29 6440 bytes
SHA-256: b46e1bb1ce712c597f79aebabb74eee9ed80499ff7f336fe85e9039354a96543
font_04_sfnt_off0007adaf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x7ADAF 5948 bytes
SHA-256: 2760dba94bf8c72ce9ea0b9d2c69715633d7f3bf89812dfa37b3e5c06656e96b
font_05_cff_off0007ba1e.bin pdf-font-stream PDF embedded font (cff) at offset 0x7BA1E 1767 bytes
SHA-256: f929b154c1739393f86aafaa33ea11e998d4237547ea87853bf41ee35a809f31
font_06_cff_off0007be41.bin pdf-font-stream PDF embedded font (cff) at offset 0x7BE41 3549 bytes
SHA-256: 2da564aa77ed7be83abdc9c2db412b62ed648ac7b3ace1ee84e4748d253f2a22
font_07_cff_off0007cb67.bin pdf-font-stream PDF embedded font (cff) at offset 0x7CB67 7073 bytes
SHA-256: 26742da0e57b265b55cbcfc487443296d46f82eb8707e6517b9a4968fa675a6a
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.42, consistent with packed or encrypted content.
font_08_cff_off0007e3c1.bin pdf-font-stream PDF embedded font (cff) at offset 0x7E3C1 7042 bytes
SHA-256: 4e850c53faa0e66014ecbc97db8ee6328db8a114809ee3ff2aecd2e894efe2d3
font_09_cff_off0007fa74.bin pdf-font-stream PDF embedded font (cff) at offset 0x7FA74 1915 bytes
SHA-256: 2cc8cb05e41dc348b960cb086767796c494fbe8636258dcc6dbf1ed773dc3992
font_10_cff_off0007ff62.bin pdf-font-stream PDF embedded font (cff) at offset 0x7FF62 7329 bytes
SHA-256: 79c92dda5fe77c55cda21a49184a8caff2d2f402537352979d909e8b5b8a1213
font_11_cff_off000818a7.bin pdf-font-stream PDF embedded font (cff) at offset 0x818A7 4793 bytes
SHA-256: 2c7746eb32712e6328a9ae394afdd9cb6eb32a97da86e79b7bcb2f83f373a0bc
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.42, consistent with packed or encrypted content.
font_12_cff_off00082a92.bin pdf-font-stream PDF embedded font (cff) at offset 0x82A92 4406 bytes
SHA-256: 331559013bae1bed3d2b9ef4a93ff99963b516e528574f4c371a798d67a715cc
font_13_cff_off0008398a.bin pdf-font-stream PDF embedded font (cff) at offset 0x8398A 2935 bytes
SHA-256: 588a76db61e4e267ee8494840bef04e170a79ab4a688563a08a03608d15294ba
font_14_cff_off0008440b.bin pdf-font-stream PDF embedded font (cff) at offset 0x8440B 2398 bytes
SHA-256: b38a8d799134f8c45e5c24f42fbd86cdd1230a86b6d9e06e42bfb97e2bc445ef
font_15_cff_off00084dd5.bin pdf-font-stream PDF embedded font (cff) at offset 0x84DD5 1041 bytes
SHA-256: a3030d0f8714b4bddccc5833bbf4b088240201959563acc822f3e56c6ccc5dfd
font_16_cff_off00085229.bin pdf-font-stream PDF embedded font (cff) at offset 0x85229 257 bytes
SHA-256: c67313452626498cd4d0733b4523b9ecb70a75e0a5c5c686858f095bd5ae119c
font_17_cff_off00085365.bin pdf-font-stream PDF embedded font (cff) at offset 0x85365 1446 bytes
SHA-256: 06970a84f1da06d8f2a248cea2824b8078e11e77d6e0b119de5bbfbf49a69ac7
polyglot_child_pdf_off00030ed0.pdf polyglot-child-pdf Secondary PDF body inside pdf container at offset 0x30ED0 567761 bytes
SHA-256: ea39084b3fdf994b1f6966c8360a02af781c1fe80990fa8351701ac6ac9f0b90