Malicious PDF — malware analysis report

Static analysis result for SHA-256 a91c3bb780685cb0…

MALICIOUS

PDF

42.2 KB Created: 2020-08-12 05:56:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2026-05-08
MD5: 4feed70aa356f617f85ff8b6a3550029 SHA-1: 4ba7180e0ae868f5a5a730b22647e1c60a2d583b SHA-256: a91c3bb780685cb0a64552eaec36b4b7270c0ebe4bcecc0bb4803b646bbbc05d
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links, identified as a link farm, with a critical heuristic firing for a malicious redirector. The document body, though heavily obfuscated, contains text related to PDF conversion and a URL that matches the malicious redirector. This suggests the primary goal is to trick the user into clicking the link to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://ttraff.com/wb?keyword=pdf%20to%20word%20converter%20online%20free%20best%20quality In PDF document text
    • http://files.kinderoopreschool.com/uploads/1/3/0/7/130740586/kajeninu_razuwup_vizudoxod_jejizujopevi.pdfIn PDF document text
    • http://files.kingstonbikeservices.co.uk/uploads/1/3/0/8/130814014/d51b86eafb80a.pdfIn PDF document text
    • http://files.mvequestrian.org/uploads/1/3/1/4/131406068/mezigejota-vulizusikape-daxugabop-babubo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://cdn.shopify.com/s/files/1/0434/2808/5912/files/jowigapuxavowafagine.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0437/2761/8209/files/lideva.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/0667/3575/files/37725769342.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0434/0904/7708/files/wigawisotapeso.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0448/6584/7458/files/95405470515.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/6991/5814/files/possessive_nouns_exercises_for_beginners.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0436/9360/5014/files/descargar_biblia_de_estudio_arcoiris_gratis.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/2004/1886/files/32701104146.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/81236671698.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/2168/1315/files/dixejijuwifunov.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/79265304831.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/4599/4146/files/15528676564.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0429/8034/3967/files/bsc_maths_syllabus_2020.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/6908/7642/files/78701393634.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
🗂 Part of campaign: kinderoopreschool.com 3 samples

Related samples 2

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_off00006566.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6566 5536 bytes
SHA-256: 9876ba4db8a2906c34f01655624917142e493c3807f75387b5b8825f6c0d2e90
font_01_sfnt_off0000785e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x785E 10200 bytes
SHA-256: 52a1835cd7702bf6d7f9dcd219f3fe74158cd973dc36fdfa7cb847db4dee7ded

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