Malicious PDF — malware analysis report

Static analysis result for SHA-256 f21d8521b2f13edd…

MALICIOUS

PDF

76.5 KB Created: 2021-04-23 19:05:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: 26c4f47cf975e6833e04364f8bcc2c95 SHA-1: 11573393f12d99e2424531f9ce527a7f31114227 SHA-256: f21d8521b2f13edd426d7387fcd89c7b978a25eed2f234b71e0bf003848ec768
186 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many pointing to disposable hosting, suggesting a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were directly extracted, the PDF structure and embedded links are indicative of an attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://baarspo.ru/strik?utm_term=el+ser+y+la+nada+resumen+corto PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4420468/normal_600e5ee8c922c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403814/normal_60612b2b6e613.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4462036/normal_60461d634df25.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4408335/normal_5ff9d5ae28ef5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4457320/normal_5fe734760c0d0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421478/normal_603ad2a63dd58.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470231/normal_605d7859a2c66.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/povelenavuviw/nosuvexafi.pdfIn PDF document text
    • https://21319658-e817-4d6a-846f-872ccfe0f0c2.filesusr.com/ugd/982af2_2bd884af099640a1b7596d917902b3a9.pdf?index=trueIn PDF document text
    • https://0f4267a5-27df-427f-b7ff-de3c6d4a4cd0.filesusr.com/ugd/9e4921_8695a5b9af37424db43ea053ef7d6d10.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/wexoteluwag/anandi_gopal_all_songs_free.pdfIn PDF document text
    • https://989244f3-426d-4557-b4f1-0018dac9047c.filesusr.com/ugd/57c819_d7a97358792a423d9c5f34ff8c2a9abe.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/pidufozu/dumesixosiseraveputen.pdfIn PDF document text
    • https://a7193630-a032-4ee2-b136-33837135b76a.filesusr.com/ugd/fac845_4dae9a200b2144568666d280b76b9488.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/tetenifeme/ligagojuvab.pdfIn PDF document text
    • https://s3.amazonaws.com/befarekogol/94326629819.pdfIn PDF document text
    • https://ca108e69-7b6b-43f0-8f16-d96ebeb8a33d.filesusr.com/ugd/79e0dc_fb705bdd6e804dcbbc5b7d2159a0e16c.pdf?index=trueIn PDF document text
    • https://a6132035-7465-4fe4-be4e-2faa96c22dab.filesusr.com/ugd/cf950b_e9edee72e3ca4a5db092ec5c381c45e6.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/betefowubevat/twinkle_twinkle_little_star_piano_chords.pdfIn PDF document text
    • https://s3.amazonaws.com/wuxupewu/digital_electronics_gates.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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ebed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBED 5144 bytes
SHA-256: e7271762c4361e7469dbedd3d08dcd8cb75705330afe24f913f0c4279f9ac75b
font_01_sfnt_off0000fd5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD5C 12152 bytes
SHA-256: 2895fa4e066b99b263c7e5f455f8fcb01946b2ed30275a99076e0ac36983569e