Malicious PDF — malware analysis report

Static analysis result for SHA-256 81d63f50cd0a9985…

MALICIOUS

PDF

71.5 KB Created: 2021-09-26 20:59:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 96d18a3a3cc34eeb3375167910fe6ce5 SHA-1: 41e92c2e5fbc1cdd6b2dec1476c9942e17cc221f SHA-256: 81d63f50cd0a9985c8b261260960d98742a9762957beb7ebb2d28f19dcf118c9
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 directories or disposable hosting, indicative of a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest 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 0.9982

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://philabc.ru/uplcv?utm_term=best+friend+romantic+shayari PDF link annotation
    • https://digbijoynath.in/uploads/userfiles/files/34502687648.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/20aa3942559b823d82a8fd1a913a4356/zemolekosoj.pdfIn PDF document text
    • https://adetexfoamgroup.centralcms.cloud/galeria/files/risesuz.pdfIn PDF document text
    • http://sartoriaventurini.com/userfiles/files/37819667735.pdfIn PDF document text
    • http://aurora-c.jp/files/files/41118818604.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614139e4d38ef---gatabexojeguxirufa.pdfIn PDF document text
    • http://kozelsk-adm.ru/files/uploads/files/66986788574.pdfIn PDF document text
    • http://abbeytraining.net/userfiles/file/8157782903.pdfIn PDF document text
    • http://tygodnikzuzlowy.pl/ckfinder/userfiles/files/kegokirilonokimadidi.pdfIn PDF document text
    • http://beautybybelief.com/admin/images/file/13685196922.pdfIn PDF document text
    • http://icmasistemas.com/userfiles/files/4431865850.pdfIn PDF document text
    • https://mobilaide.com/upload/editor/file/94993294169.pdfIn PDF document text
    • https://immo-cjeanpaul.lu/userfiles/files/32536982374.pdfIn PDF document text
    • http://evergladesharvesting.com/ckfinder/userfiles/files/16868541836.pdfIn PDF document text
    • http://legalinet.eu/userfiles/files/velajis.pdfIn PDF document text
    • http://palestraarkadia.it/userfiles/files/guwijajujodasupekiwepodo.pdfIn PDF document text
    • http://fujavietnam.com/images/Download/52751649802.pdfIn PDF document text
    • http://tctrack.vn/images/newtech/files/18767508182.pdfIn PDF document text
    • https://websbag.com/uploads/files/poludimedomuro.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141f997b7f99---pitiwuvigixudexuxu.pdfIn PDF document text
    • https://datenglagi.com/contents/files/zobekegovisarol.pdfIn PDF document text
    • http://apothepharma.com/upload/files/xeguwimudedizavon.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_off0000b118.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB118 10860 bytes
SHA-256: 04f38c723c1cd72c6258427e800bb77485bc621cb157f1816c40be3c0d247211
font_01_sfnt_off0000ca0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA0C 17740 bytes
SHA-256: 1bd01a5dccbff30a9a6af8fccf68232222fec053c0c2b5f09d5244613fbcde48
font_02_sfnt_off0000f84d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF84D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1