Malicious PDF — malware analysis report

Static analysis result for SHA-256 50451194281b3422…

MALICIOUS

PDF

95.9 KB Created: 2021-09-06 20:44:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 8fa309dfa7c7ea02a5dfab8224e94020 SHA-1: a6cf3fdaf24dbfdf6f10acef53569a6cff00551d SHA-256: 50451194281b34229f763f99ecddf72b72b74cbb7b11756e91bf7a1cffab6b8c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest a phishing or trojan payload is intended. No scripts were extracted, but the primary attack pattern is the use of malicious links within the document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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
  • 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://cructi.ru/uplcv?utm_term=cours+de+recherche+operationnelle+gratuit+pdf PDF link annotation
    • http://lachina.cn/upload/file/wiwexopefexon.pdfIn PDF document text
    • https://smartmedia.ro/app/webroot/files/userfiles/files/6717988270.pdfIn PDF document text
    • http://www.supercarrentalsofmiami.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3c2ad5cd60---pojinuzurisukivunisasuz.pdfIn PDF document text
    • http://uteambio.com/upload/files/gawuzifedo.pdfIn PDF document text
    • http://monterroso-construpuntos.com/campannas/file/tobobumevelosizi.pdfIn PDF document text
    • https://bojovicsirogojno.com//files/xanigiv.pdfIn PDF document text
    • http://arcstema.com/userfiles/files/62410523713.pdfIn PDF document text
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b34366d085---6627408683.pdfIn PDF document text
    • http://insightonafrica.in/userfiles/file/87051953935.pdfIn PDF document text
    • http://gartenstadt-apotheke.com/userfiles/file/41972217039.pdfIn PDF document text
    • http://smflow.in/admin/uploads/file/tenipe.pdfIn PDF document text
    • https://larrialdiak.es/files/galeria/files/sasorudapisuverodolelokis.pdfIn PDF document text
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f3790d1b4bc---74993135378.pdfIn PDF document text
    • http://hrzservices.com/uploadfiles/file/87144537944.pdfIn PDF document text
    • http://skrabl.pl/www/rpbd/fck/file/60919033828.pdfIn PDF document text
    • https://mygamedaysports.com/wp-content/plugins/super-forms/uploads/php/files/b31d540fb832e5882010f74cb6c772f0/veduxe.pdfIn PDF document text
    • http://adirondackseafood.com/ckfinder/userfiles/files/wegebigixakojumuwubat.pdfIn PDF document text
    • http://www.papelerialapiceros.es/ckfinder/userfiles/files/repakokuvurugimitezesi.pdfIn PDF document text
    • http://gpe-el.pro/ckfinder/userfiles/files/likomuri.pdfIn PDF document text
    • https://air-separation-supplier.com/d/files/fozalizarofujirunibanuz.pdfIn PDF document text
    • http://xn--80aaa1acmiejxr6d7fg.xn--p1ai/data/files/lawitulow.pdfIn PDF document text
    • http://ingpiazza.eu/userfiles/files/81598800406.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://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_off000103ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103BA 24436 bytes
SHA-256: 677043f8c867ebf51ce16ae10d5ebcae5f4940faa9914d9cbe2250c9bb136eac
font_01_sfnt_off00014011.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14011 11028 bytes
SHA-256: 380263a6017f84033a51b479bd54be6c2994e678465a88ccc53af26143eaecf0
font_02_sfnt_off0001597e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1597E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1