Malicious PDF — malware analysis report

Static analysis result for SHA-256 7939d3f55979b607…

MALICIOUS

PDF

75.9 KB Created: 2021-06-21 08:01:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: b59f7e64879e5c786475e252de099bc3 SHA-1: 2e147d38c0255965ec62746ce464f6e49619e940 SHA-256: 7939d3f55979b607e11afbed7d3fe223275b1b16fc5df639c584b17f1e785db7
156 Risk Score

Malware Insights

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

This PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links pointing to compromised WordPress upload directories, suggesting a link farm designed to host and distribute malicious files. The presence of embedded URLs and the nature of the heuristics indicate an attempt to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/160c6ba785ab2b---40550952456.pdf In PDF document text
    • http://roughriders66.com/clients/f/fa/fa96273273f04fd2a06feef12b1e4d70/File/sotimexojevovuzojum.pdfIn PDF document text
    • http://wchs67.com/clients/f/fd/fd50fd9748f3592dabdfdad26f378f15/File/76718218673.pdfIn PDF document text
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b3c208435e7---kedavalalumukumuvipawi.pdfIn PDF document text
    • http://www.cafeinca.com/img/public/contenido/file/tojejugalozemo.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/gosabi.pdfIn PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a4ed2d6918f---65503939428.pdfIn PDF document text
    • https://viajespereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608abb7a9d974---28530165993.pdfIn PDF document text
    • https://sieompaysdebray.fr/lesiom/txt/imgadmin/file/nanakoguritorabi.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7fb0b4e0b3---tozejenepijidulutav.pdfIn PDF document text
    • https://shinyjewellers.com/wp-content/plugins/super-forms/uploads/php/files/963u2q1000080g6mm2kd8kk6fk/97230071154.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608cf60c57b9d---24062635840.pdfIn PDF document text
    • http://agcslohian.com/userfiles/file/10628749693.pdfIn PDF document text
    • http://fkhd.cz/data/img/79343132406.pdfIn PDF document text
    • http://laclonghotel.vn/upload/files/96390120467.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=sugar+plum+cuppy+cake+songPDF 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://scripts.sil.org/OFLIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c76f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC76F 5524 bytes
SHA-256: 7bb8f146de5101da6f7bef0c85bd0f20714ed35cd16d1b62e9741b70baf5f3de
font_01_sfnt_off0000da2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA2F 13088 bytes
SHA-256: 56cf1e61ea965130673102fb9d8da3635c84e20c5c4ad4317b60c4bbbb5d1c38
font_02_sfnt_off00010415.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10415 16576 bytes
SHA-256: 7a765f25c115bfaf2195df0135458eaa079d01bd2ba78c979ddced1684d42e4a
font_03_sfnt_off00011aa5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AA5 1736 bytes
SHA-256: 74be5bc4d46f64e5c506ae1006f7022dc98ebf960e37c7bf417c2027ca73106d