Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c45ae59bd6f6de5…

MALICIOUS

PDF

82.5 KB Created: 2021-03-01 22:45:12 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2026-06-04
MD5: 55f267a2eb93dc139fe5f1d3adfe4b93 SHA-1: a9b1def714fed8e1d7ee5d27a027975e55267939 SHA-256: 8c45ae59bd6f6de50db0f9c8eb831b1d3d85b5a8651504ac0da49e0ba95f2dcf
196 Risk Score
Tags
free-cdn-ebook-manual-lure

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal a link farm and SEO redirector pattern, with URLs like 'https://nipisod.ru/123?utm_term=arthur+combs+humanistic+learning+theory+ppt' likely serving as lures to phishing or malware download sites. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create malicious PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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.
  • 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 https://nipisod.ru/123?utm_term=arthur+combs+humanistic+learning+theory+ppt PDF link annotation
    • http://fotubobuwenapu.scienceontheweb.net/38569354799.pdfIn PDF document text
    • https://sifejolo.weebly.com/uploads/1/3/1/4/131410009/77722a.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4379603/normal_5fdf91c26087a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4471481/normal_6011ab8c5150c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481411/normal_6029ef603af81.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4453344/normal_5fe7840c8fd9f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4451762/normal_5fc7be5a84e3e.pdfIn PDF document text
    • http://lenugaguv.medianewsonline.com/what_is_human_development_in_biology.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420767/normal_600f4c570bb2b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4494889/normal_600eacc76682b.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://totuxivez.onlinewebshop.net/yamaha_ypg-635_midi_driver.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/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://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000106a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106A1 5576 bytes
SHA-256: 894331022af3f1c4bf9161fc10cae54413e327aceaf3a1fdbe4abe8b3f338e8e
font_01_sfnt_off00011975.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11975 10600 bytes
SHA-256: 1a6ef320507407c53bfbdd2f6d7b4eccc26a270f2e92204eb4bf5b44aa5ec4ed

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