Malicious PDF — malware analysis report

Static analysis result for SHA-256 85673f1a9ceb00fb…

MALICIOUS

PDF

82.6 KB Created: 2021-04-02 10:32:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 0ed32d1e9053cb770f4abeb53e385ddb SHA-1: d0c091ca5f2cd352c12e6e00c925c842796217e2 SHA-256: 85673f1a9ceb00fb88e0d8479362ac26056b79cb49d150505d63f04232e83523
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to disposable domains, indicative of a link farm or phishing lure. The ClamAV detection and ML classifier strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a phishing or SEO manipulation attack, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://dugedepap.ru/strik?utm_term=what+order+should+you+read+the+selection+series PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4402519/normal_60137de4ebff6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4478664/normal_5fe6a2b1312ac.pdfIn PDF document text
    • http://businessmentality.com/morefexakanoripuvegadawem55y1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450635/normal_5fd87d7419470.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454973/normal_5fd1e28a423a7.pdfIn PDF document text
    • http://summerita.fun/okay_madam_full_movie_netflixnhfmd.pdfIn PDF document text
    • https://komamezumef.weebly.com/uploads/1/3/1/3/131398541/7816829.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4486522/normal_5ffb23903dd68.pdfIn PDF document text
    • https://jadivamanug.weebly.com/uploads/1/3/4/8/134868371/7ccc58a2.pdfIn PDF document text
    • http://girlita.space/rupomunemipopekalwkvij.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4386620/normal_6023ead2b6b98.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4499334/normal_604f070463a0d.pdfIn PDF document text
    • https://kagebavewijove.weebly.com/uploads/1/3/0/7/130740568/7500077.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4390051/normal_60646afb1336c.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/kokesatodixon/josegetokesatapabak.pdfIn PDF document text
    • https://s3.amazonaws.com/xuzakob/links_awakening_guide_ign.pdfIn PDF document text
    • https://s3.amazonaws.com/petuzutemixuvod/investigative_reporting_workshop.pdfIn PDF document text
    • https://s3.amazonaws.com/tuzakifezara/85936700213.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fa8b426f-c6f6-410e-a1aa-af48c4ad9596/58359451803.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c55f1b76-c883-45de-9395-3d8f594b0f41/9_11_wallpaper_for_facebook.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://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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ef48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF48 5144 bytes
SHA-256: 0b5c8c3690b7635a003f978c0e959f2bcde5dcfab1b0b9ecbb78869b30210428
font_01_sfnt_off000100cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100CF 10868 bytes
SHA-256: 956177b614c2f64d6f0bcd49c7484bf6ba5c99010c8778109e7c919afb734f20
font_02_sfnt_off000125cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125CF 16076 bytes
SHA-256: d286e8b4d1cdafc5f769987bdccf7a6368ad55d0d3b8f98fd56bc2ae223999f8