Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac86fbe7e3a1339c…

MALICIOUS

PDF

75.0 KB Created: 2021-09-23 14:17:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: a356ccb075624259aef53290c6802bab SHA-1: ea1f092b56c7b540b5d7f7dd4519a24238f76f2e SHA-256: ac86fbe7e3a1339c7ebec3eee2c09ea0efdc1b691b86661270edf71807add96d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to distribute malware or phish users. The ML classifier and ClamAV detection strongly indicate malicious intent. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious document delivery mechanisms.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161493e74d21b6---nexopajuren.pdf In PDF document text
    • http://wsystem.sk/userfiles/files/13144734898.pdfIn PDF document text
    • http://rabotatver.ru/userfiles/admin/bakulinuzerilogefinot.pdfIn PDF document text
    • http://ubestsports.com/imager/files/20210902165802.pdfIn PDF document text
    • https://artesapanaderia.xyz/aym_image/files/3427520169.pdfIn PDF document text
    • http://soluzionebenessere.eu/userfiles/files/40949451860.pdfIn PDF document text
    • http://asbu.net/uploads/FCK_files/file/33338563330.pdfIn PDF document text
    • http://metalzilembo.it/userfiles/files/dikavudirolabomifur.pdfIn PDF document text
    • http://athaj2.specialty-match.com/upload/files/muvobedemuwunikiwe.pdfIn PDF document text
    • https://volnynaklad.cz/data/file/diwojafozi.pdfIn PDF document text
    • http://grapes4u.ca/sites/all/sites/grapes4u.ca/files/menewimiz.pdfIn PDF document text
    • https://dentrangtrisaigon.net/images/uploads/files/sonumibokopopez.pdfIn PDF document text
    • https://condominiovillage.com/userfiles/file/46938934992.pdfIn PDF document text
    • http://crmloccitanecr.com/campannas/file/xorewivixubezolilaz.pdfIn PDF document text
    • https://turdv.ru/SITE/files/editor/file/45924211846.pdfIn PDF document text
    • http://xn--42-jlclgg6a3e.xn--p1ai/userfiles/file/32211427480.pdfIn PDF document text
    • https://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/161416719b7ca6---92748824684.pdfIn PDF document text
    • https://hyundainhapkhau.vn/upload/files/2659298178.pdfIn PDF document text
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/102ccd60aeb80fb35568798daefbcf40/45795091318.pdfIn PDF document text
    • https://filetorme.com/upload/files/43256683401.pdfIn PDF document text
    • http://tarnava.eu/user_images/file/lifikipidogugerete.pdfIn PDF document text
    • http://stattus.com/assets/file/pujoradokikopasoz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=live+cricket+tv+apk+downloadPDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c14a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC14A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d961.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD961 10540 bytes
SHA-256: 454764eae16bebb74840480ba5ed40f91dc1ac0e9c1280571aad2aeeec4ad986
font_02_sfnt_off0000f18d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF18D 17644 bytes
SHA-256: c0d12e0ae8c9d9bb0e225fe1d70ece96672aeaa3fa14b5108d2f477c6ed36677