Malicious PDF — malware analysis report

Static analysis result for SHA-256 dde967f3e4f1935a…

MALICIOUS

PDF

76.9 KB Created: 2021-06-12 04:12:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 740eec8c7f67fc5f88aa9134f9c8d2e4 SHA-1: c6e8ce1ae048f8bf09e2eb59a6fd85a7a135f31d SHA-256: dde967f3e4f1935a7b5bb39b7d0ded39aacd2a74b73444cd7d49489e5e96afbf
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to PDF files hosted on various domains, some of which appear to be compromised WordPress installations. The presence of external URI heuristics and the PDF_SEO_DISPOSABLE_LINK_FARM rule further support this. The document body is heavily obfuscated and unreadable, suggesting it may contain embedded scripts or exploit code, though no specific script content was extracted.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://inwebjor.ru/uplcv?utm_term=bard+instruments+dnd PDF link annotation
    • https://arch.ua/ckfinder/userfiles/files/35737671804.pdfIn PDF document text
    • https://steklo-shik.ru/userfiles/file/37706199984.pdfIn PDF document text
    • http://yjsyrj.com/userfiles/file/kowatoregal.pdfIn PDF document text
    • https://realestateconnect.biz/wp-content/plugins/super-forms/uploads/php/files/pqfppve0203cacpl0idvn5be37/10878539374.pdfIn PDF document text
    • http://alarcon-v.com/editor_upload_image/file/90651262438.pdfIn PDF document text
    • http://www.grundys.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160bbf5bc1739c---gofipogukopalufod.pdfIn PDF document text
    • https://bursac.net/userfiles/file/vijenenek.pdfIn PDF document text
    • https://juhaszautovill.hu/userfiles/file/34802004330.pdfIn PDF document text
    • https://oklogistic.lv/upload/file/69003546194.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607ee6952a62d---86504714717.pdfIn PDF document text
    • http://www.hotel-margherita.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abaafd851d7---79457196172.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/ruvh7qte78mj4ou7c5r0673f6m/pinuto.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/bpj4uptdd6caaeon9tvfsl7a92/61214388484.pdfIn PDF document text
    • https://atcotourismtravel.com/userfiles/file/jegadojedukavixub.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/160893a25f3b4f---57940827292.pdfIn PDF document text
    • https://www.litesourcenc.com/wp-content/plugins/super-forms/uploads/php/files/4f7d1b72f0680a55a0a9a7be885f7bca/53837525393.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e40e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE40E 4760 bytes
SHA-256: 83b218fd9ac8022f01033d358247de6e161a4d19c0a18ca8dcfbecddfe99d0cd
font_01_sfnt_off0000f413.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF413 10728 bytes
SHA-256: 920d671f5f2085412eeeacfce6691e9a284ffa045d7022284db8ee0acdad17d8
font_02_sfnt_off000118cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118CD 4324 bytes
SHA-256: d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378