Malicious PDF — malware analysis report

Static analysis result for SHA-256 37875cd284f41f2a…

MALICIOUS

PDF

81.0 KB Created: 2021-09-18 08:11:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: f2004af33fe1b953b99724909cab76df SHA-1: 53c9439aff236ae17f2c07326828753ea0c9f5c7 SHA-256: 37875cd284f41f2a65beb0c5e920f9fbd9f9ec1718523ca78f3628398d99b2ca
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, suggest a link farm designed to redirect users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics indicates a sophisticated effort to obscure the true destination of the links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://drafthe.ru/uplcv?utm_term=how+to+set+ringtone+for+outgoing+calls PDF link annotation
    • https://autotrilogy.com/wp-content/plugins/super-forms/uploads/php/files/5e96a855c2589ce3fca5aab338cfd393/lowerapufiredama.pdfIn PDF document text
    • https://auto-rujo.com/images-editor/file/15355904219.pdfIn PDF document text
    • https://hogozaty.com/ckfinder/userfiles/files/30963095482.pdfIn PDF document text
    • https://terminal.hr/userfiles/file/99729594018.pdfIn PDF document text
    • http://joelcsimonesq.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/sifalukaverenixez.pdfIn PDF document text
    • http://mixline.ru/img/lib/file/47072098867.pdfIn PDF document text
    • https://digbijoynath.in/uploads/userfiles/files/63647022293.pdfIn PDF document text
    • http://doubles301.jp/files/ckeditor/files/19054399935.pdfIn PDF document text
    • http://labuchedeberce.fr/userfiles/file/ketaxafopo.pdfIn PDF document text
    • http://terredellamagnagrecia.com/userfiles/files/fizanab.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/161355779603e3---diwibudufi.pdfIn PDF document text
    • http://agavietnam.com/img/files/wasibixunusenukoje.pdfIn PDF document text
    • https://vasantviharproperties.com/userfiles/file/46425705744.pdfIn PDF document text
    • https://techielingo.com/fck_uploads/files/99954410794.pdfIn PDF document text
    • https://diamond-marketing.cz/soubory/sudigasukilivoxalaf.pdfIn PDF document text
    • http://gps-ambroisie.com/ressource/site-image/files/dubakuzafaje.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/uqlmdofiq354ggo61tfb96tpm5/22720399826.pdfIn PDF document text
    • http://61kidsclub.com/userfiles/file/beverixu.pdfIn PDF document text
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/7bd25c0150d8579ebc4c17fc5882acc5/75160651326.pdfIn PDF document text
    • http://dptour.net/bot/ckfinder/uf/files/dejekewuvufotofuwonuj.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/16143bb4a9b85f---jefafalutanutuz.pdfIn PDF document text
    • https://melz-feu.ru/upload/titemapew.pdfIn PDF document text
    • http://cluster006.ovh.net/~greeters/be/ckfinder/userfiles/files/pojamepe.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_off0000d6ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6EF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef06.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF06 10688 bytes
SHA-256: 791793978de845ed26329bd6707f24758834e26c1134e376e4c70135d6aaa024
font_02_sfnt_off000107b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107B7 18044 bytes
SHA-256: 890552bd5a7ef0259813b700ec0567792af8c6e2e05639d5f890d9a1a951e084