Malicious PDF — malware analysis report

Static analysis result for SHA-256 71c3e01aabb82d09…

MALICIOUS

PDF

85.5 KB Created: 2021-06-24 02:45:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-24
MD5: 7163a6d0afcdcc87d415b4e6fb74a18c SHA-1: 7f1aba51b5724849d9da92c6cf20a7c3cd28cb89 SHA-256: 71c3e01aabb82d09a78525dfbc2b14029d46a1ec9afa35ee127d661d3a92a46d
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains a link farm pointing to numerous compromised CMS upload storage locations and disposable hosting sites, suggesting a phishing or malware distribution scheme. The presence of embedded URLs and the nature of the heuristics strongly suggest this document is part of a spearphishing campaign.

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://my-natural-style.net/upload/files/vanotaguvixadutex.pdf In PDF document text
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/0ad788e79dde108f9282b36818e3bb73/zedipokusi.pdfIn PDF document text
    • https://popcouncilinstitute.org/wp-content/plugins/super-forms/uploads/php/files/79be36a652f3b4a9e1bb0dea84ba817b/70047125743.pdfIn PDF document text
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/d832d47afd9bdeebeffb433906e5d0a9/54887626747.pdfIn PDF document text
    • https://xosobacninh.vn/webroot/img/files/ritewotiju.pdfIn PDF document text
    • https://aadhaarretail.com/administrator/imagetemp/file/rumudijuranotusev.pdfIn PDF document text
    • http://maslag.eu/userfiles/file/10474514366.pdfIn PDF document text
    • http://bioident.pl/photos_fck/file/nutolevibovalub.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c89dff6706a---jelawa.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608565b185439---sipibezelapigalukiva.pdfIn PDF document text
    • https://svetpoznaniyaonline.ru/wp-content/plugins/super-forms/uploads/php/files/843357823bec681c5904ab52e3a6aa88/puwabedotikoxafizute.pdfIn PDF document text
    • https://iwnta.com/userfiles/file/53158862946.pdfIn PDF document text
    • http://xn--b1ahhafccpgkb2bxo.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/77fd5e2db401cff1fee96239e44de41c/78158553883.pdfIn PDF document text
    • https://tramtron.vn/uploads/files/files/31834616766.pdfIn PDF document text
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/c22096ecfc0262e972c5b31a75e8efde/jugosaxobu.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
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=exercises+for+c5+c6+bulging+discPDF 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

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010267.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10267 5224 bytes
SHA-256: 91f95b774bb4bc61483564dfea1cbd44450b7a4bd8fa93b452309e96bbc47591
font_01_sfnt_off00011430.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11430 10792 bytes
SHA-256: 2f7f5f2b9e1a3de7c11428a11188e1263f40d8b685d5eaab63f6e94f5a4b5ed8
font_02_sfnt_off000138f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x138F9 4324 bytes
SHA-256: b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c