Malicious PDF — malware analysis report

Static analysis result for SHA-256 c526202c96bd0387…

MALICIOUS

PDF

81.6 KB Created: 2021-09-14 13:24:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: b061aa2b1763c6d2d87012da1c1a273b SHA-1: c5caec7605b1dc3df054fd2375bcd84c90c51116 SHA-256: c526202c96bd0387d6c18c064c0b6ab08df93f78b492686a3d5a4b1fca9ae071
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to PDFs hosted on distinct, potentially disposable domains, indicating a link farm designed to distribute further malicious content or phish users. The `PDF_SEO_DISPOSABLE_LINK_FARM` heuristic further supports this, identifying the PDF's structure as a link farm on disposable hosting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 5

  • 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 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 http://straub-online.ch/userfiles/files/lepovujerudu.pdf In PDF document text
    • http://stonepigments.com/userfiles/file/lupefozalelunukogumenal.pdfIn PDF document text
    • https://pushtypathshala.com/demo/aims/files/images/files/dumotovanovizoxedoruralu.pdfIn PDF document text
    • https://novamakine.com/upload/ckfinder/files/91055171653.pdfIn PDF document text
    • http://integrotech.pl/zdjecia/file/74881925943.pdfIn PDF document text
    • http://lexen.ca/userfiles/files/guturan.pdfIn PDF document text
    • https://magyar-logyogyasz.hu/fileok/file/48261353824.pdfIn PDF document text
    • http://pnalog.ru/images/file/26785258374.pdfIn PDF document text
    • http://worldsocialistpartyindia.org/ckfinder/userfiles/files/1996936443.pdfIn PDF document text
    • https://tatvan.in/userfiles/file/renasulukifes.pdfIn PDF document text
    • https://ensegun2.com/ckfinder/userfiles/files/93255376327.pdfIn PDF document text
    • http://maurovalleferroarchitetto.eu/userfiles/files/siwugabix.pdfIn PDF document text
    • https://kakakmanis.com/contents/files/56133662142.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/161395c32cea86---xesezijezomi.pdfIn PDF document text
    • https://mikludava.lt/images/files/kegezebunoragivusi.pdfIn PDF document text
    • http://tinhdauvietnam.vn/upload/files/7670611329.pdfIn PDF document text
    • http://luyenthidhcanhsat.com/Images_upload/files/nimutujexoli.pdfIn PDF document text
    • http://metisentry.net/ckfinder/userfiles/files/tojanidulodibupon.pdfIn PDF document text
    • http://euro-ex.com/images/blog/file/74157301467.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613efb11cffce---95329056446.pdfIn PDF document text
    • https://sistemagestiondpr.co/userfiles/file/bugonenazosuz.pdfIn PDF document text
    • http://neoneofytou.com/ckfinder/userfiles/files/kubefobasexuf.pdfIn PDF document text
    • http://sumosushingrill.com/uploads/files/ziteteli.pdfIn PDF document text
    • https://tese.in/ckfinder/userfiles/files/9390498705.pdfIn PDF document text
    • http://pietroquatriniarchitetto.eu/userfiles/files/gudowikabuzesupurum.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=wat+is+bedrijfstijd+androidPDF 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://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_off0000da81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA81 17692 bytes
SHA-256: e6cfdd03f96d8501cc3a1f6ebbf7ba9a6b77e6313eaacd748895e2741de80142
font_01_sfnt_off000108f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108F5 10564 bytes
SHA-256: 07357574417943d7c48782421b646f3e0634a9b9b8fc9912ba3702cadd0c66a6
font_02_sfnt_off00012131.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12131 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1