Malicious PDF — malware analysis report

Static analysis result for SHA-256 c65be0f8443cc001…

MALICIOUS

PDF

100.5 KB Created: 2021-09-14 13:09:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: ed87fc653d054a4993b1fa79c5ec0cfd SHA-1: a34e919507c76c2c46fa1bd280b018cdf234a457 SHA-256: c65be0f8443cc001ee0a3f9581fe2276c0514379bfd0e9ad9b3275934478eb1e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to potentially malicious or unknown domains, suggesting a phishing or redirection attempt. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic indicates a deliberate attempt to create a link farm, likely for SEO manipulation or to host malicious content. While no scripts were explicitly extracted, the presence of external URIs and the ML classifier's high confidence score support the classification as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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://old.bgk-meshkova.com/ckeditor/ckfinder/userfiles/files/dumafifaminez.pdf In PDF document text
    • http://xinghui.co/upload/ckimg/files/202109051501468379.pdfIn PDF document text
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fb97f4862b---malatavexamil.pdfIn PDF document text
    • https://rumahbaruku.com/contents/files/98959120851.pdfIn PDF document text
    • https://indoshaolinkungfusociety.com/ckfinder/userfiles/files/fimegezekaximojajowag.pdfIn PDF document text
    • http://dainindo.com/Uploads/userfiles/files/nizekebodekax.pdfIn PDF document text
    • http://pitchdecor-construction.com/user_img/files/93955781022.pdfIn PDF document text
    • http://bentleyplemtech.ru/userfiles/file/24256181331.pdfIn PDF document text
    • http://brucemayrockinstitute.com/assets/ckfinder/core/connector/php/uploads/files/vubudivevilagizabojafu.pdfIn PDF document text
    • http://oumkua.com/userfiles/file/22181606655.pdfIn PDF document text
    • http://www.elstar.ru/uploads/files/52885796749.pdfIn PDF document text
    • http://chongqinghaohong.com/upload/files/bedomi.pdfIn PDF document text
    • http://bowlingkillers.com/imgdb/files/44640451542.pdfIn PDF document text
    • http://artsar.pl/userfiles/file/dodorovalopi.pdfIn PDF document text
    • https://christianklein.eu/Quansis/ckfinder/userfiles/files/9890495485.pdfIn PDF document text
    • https://al-wesam.com/userfiles/files/bedatokageximu.pdfIn PDF document text
    • http://www.77ice.com/upload/files/34994203737.pdfIn PDF document text
    • http://fioredda.com/userfiles/files/61259769690.pdfIn PDF document text
    • http://hostingureitings.lv/uploads/userfiles/files/85495418928.pdfIn PDF document text
    • http://ohxto.com/uploaded_files/userfiles/files/64279771481.pdfIn PDF document text
    • http://njuhome.pl/ckfinder/userfiles/files/juvakerod.pdfIn PDF document text
    • http://findmealocalpainter.com/insurazon/admin/userfiles/file/73878405615.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/98e1f6c95d3adef0d5162bf2dc5690a1/kopebixenanejeleropatokiz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=programming+in+c%23+balagurusamyPDF 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_off000123ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123AD 19452 bytes
SHA-256: 2516d529dd7e7277571a28be56cb71c312f04bcfd90e972a1cb3992c58c5280a
font_01_sfnt_off000156e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x156E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00016ef8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16EF8 10128 bytes
SHA-256: 57298c31476be38796e49be2c2bd0c1d650c6ebd7aef637e06ca29755c804607