Malicious PDF — malware analysis report

Static analysis result for SHA-256 786a491e3701cf50…

MALICIOUS

PDF

81.2 KB Created: 2021-10-07 05:13:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 4a12d635798055131811327c7d73cc52 SHA-1: d88192942f1273d157c2f00c8131f998020ed0e4 SHA-256: 786a491e3701cf5078f5f290f9ffe24d5927050a1d525ac9948cea407bbc1bb5
166 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains numerous external links, with a high-confidence heuristic indicating a link to an algorithmically-generated URL, suggesting a phishing or malware distribution attempt. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this by identifying it as a link farm on disposable hosting. No scripts were extracted, but the presence of multiple external URLs points to an attack pattern involving directing users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://nhuaduongnhapkhauaz.org/upload/files/sulasebarakavolezes.pdf In PDF document text
    • http://cesishotel.com/res/wysiwyg/file/56135234165.pdfIn PDF document text
    • https://ecableapp.com/FCKeditor/FCKimgUpload/file/vupupin.pdfIn PDF document text
    • https://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/1615e31a55626e---dakonaj.pdfIn PDF document text
    • http://www.vegagastro.pl/upload/file/zavamo.pdfIn PDF document text
    • https://ijacr.net/assets_admin/ckfinder/core/connector/php/uploads/files/basobogabasofo.pdfIn PDF document text
    • https://ambulatorioveterinariosismondi.eu/file/24258697891.pdfIn PDF document text
    • https://receptabc.hu/images_banner/files/lozomuvixufadupararot.pdfIn PDF document text
    • https://samngaimarble.com/html_upload/file/jajexopizop.pdfIn PDF document text
    • http://keitbg.com/images/files/firujoxidedef.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/bd0ab1bb41d479630d04099cfc271fbe/49738965474.pdfIn PDF document text
    • https://www.ijdsir.com/ckfinder/userfiles/files/givuzabusepabineme.pdfIn PDF document text
    • https://duel.pl/userfiles/file/84586409983.pdfIn PDF document text
    • http://degeninhotel.ru/admin/ckfinder/userfiles/files/pepij.pdfIn PDF document text
    • http://ih-consultant.com/ckfinder/userfiles/files/93815192022.pdfIn PDF document text
    • https://network-italia.com/file/98270800551.pdfIn PDF document text
    • http://voyagevietnamlaos.com/hinhanh/file/96761037205.pdfIn PDF document text
    • https://tomorrowhubs.com/upload/users/files/38843111024.pdfIn PDF document text
    • http://sadiqandsons.com/userfiles/files/redujonakimewidojizasili.pdfIn PDF document text
    • http://agataklimowska.pl/userfiles/file/76626776925.pdfIn PDF document text
    • http://pnalog.ru/images/file/74581752298.pdfIn PDF document text
    • http://ksiclubbiz.ksiclub.org/svnprojects/DHD/Source/images/files/96778895267.pdfIn PDF document text
    • http://aisne.proximeo.com/ckfinder/userfiles/files/maniboxixudutupivagupuzo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=swelling+in+one+leg+and+footPDF 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_off0000d7f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7F3 18476 bytes
SHA-256: 23fd34fed527d89f1fb9c4f1d4588b6517beb78a5cf38ebe87c6d8226bf9be0b
font_01_sfnt_off00010821.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10821 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012038.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12038 10424 bytes
SHA-256: 5d3a92dd8168fcde2c8a2492ea856151ff36cb2b9077158fde101ddc2eb65118