Malicious PDF — malware analysis report

Static analysis result for SHA-256 31dd4733102a9af1…

MALICIOUS

PDF

72.4 KB Created: 2021-10-03 06:54:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 019ef7eabf1971e33a3387119943bc63 SHA-1: d321f9f6a888223e354b2027025770a59446b68d SHA-256: 31dd4733102a9af132faaf3f36aefeadcc7d215c013647dc8264c4f105697bfb
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs pointing to external sites, suggesting a phishing or credential harvesting campaign. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this, indicating a pattern of using numerous links on disposable hosting. No scripts were extracted, but the overall structure points to a malicious document designed to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9915

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://culfordequestriancentre.org/UserFiles/file/81213710419.pdf In PDF document text
    • http://e-pisanie-prac.pl/famprojekt_z_serwera/images/file/320576168.pdfIn PDF document text
    • https://spitalmoldovanoua.ro/ckfinder/userfiles/files/nuxafuxeloguveguw.pdfIn PDF document text
    • http://utcsp.rustyramone.com/uploads/files/pemafijubojumajop.pdfIn PDF document text
    • http://luluscafeonline.com/uploads/files/66853820896.pdfIn PDF document text
    • https://netshopnepal.com/userfiles/file/98802922090.pdfIn PDF document text
    • http://elpijisystem.com/file/79236019007.pdfIn PDF document text
    • http://duancanhotot.com/upload/files/73074016393.pdfIn PDF document text
    • http://ancheng-medical.com/uploadfile/files/duwukikuruwogipukos.pdfIn PDF document text
    • http://www.vishalsahni.com/public/ckfinder/userfiles/files/24630743493.pdfIn PDF document text
    • https://www.parquesanalbertohurtado.cl/ckfinder/userfiles/files/51283277655.pdfIn PDF document text
    • http://topnotchimports.com/ckfinder/userfiles/files/1028908853.pdfIn PDF document text
    • https://grootformaatspandoeken.nl/userfiles/file/68026160143.pdfIn PDF document text
    • https://prevodi-plovdiv.com/userfiles/file/xifozagilakemo.pdfIn PDF document text
    • http://kargiskola.ge/myadmin/ckeditor/ckfinder/userfiles/files/8875074756.pdfIn PDF document text
    • http://busankid.com/webfiles/board/file///danoruvo.pdfIn PDF document text
    • http://baovekhucongnghiep.com/upload/files/defuvezurubamud.pdfIn PDF document text
    • http://maimungkorn.com/UserFiles/file/67893482275.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/33606afe4ddc92e8654069740dc9da96/24081318232.pdfIn PDF document text
    • https://www.institutvzdelavani.cz/files/88043214064.pdfIn PDF document text
    • http://gamebonda.com/ckupload/files/turaxovute.pdfIn PDF document text
    • http://johndanton.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/50751066274.pdfIn PDF document text
    • http://sahcarpets.com/userfiles/file/89461083017.pdfIn PDF document text
    • http://domadoma.cz/userfiles/file/33457528057.pdfIn PDF document text
    • http://eastcity.hu/ufiles/file/7833311244.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/16136a595d5b28---jalitubuferezewalo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=self+conscious+aboutPDF 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_off0000b724.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB724 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cf36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF36 17868 bytes
SHA-256: c01141816b7b0f105661e07702e15618399b4726f05bc2b58a8fc02ec57fd0e4
font_02_sfnt_off0000fbea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBEA 10544 bytes
SHA-256: 8511593fbab00e45bd7b557b056515f5918c1d9b3f8a95581d8cd3ce9a3df1ac