Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d531b81c71342eb…

MALICIOUS

PDF

82.8 KB Created: 2021-09-19 03:15:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 4f4971ab0976a7fe922b8c078ba5f0be SHA-1: 1253f0fc487c5a6e8cfa560d0df8bc5cb381f959 SHA-256: 8d531b81c71342eb643f51e9d47474b4297726e3aa9de4616b8769c26b7d4c5d
134 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicated a high probability of maliciousness. The document contains numerous embedded URLs, many of which point to disposable domains, suggesting a link farm designed to obscure the ultimate destination. The presence of a 'download button' heuristic further supports a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://festacreativita.org/userfiles/file/tejiruneda.pdf In PDF document text
    • https://davidfauquemberg.com/home/fauquemb/david/bbdg_site/userfiles/file/69852174802.pdfIn PDF document text
    • http://zit-tech.com/userfiles/files/nuverukoxemigotozinigexix.pdfIn PDF document text
    • http://novehorizonty.sk/userfiles/file/rixolurapakixisadiwifuju.pdfIn PDF document text
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613f8258dc563---vokesigedezazag.pdfIn PDF document text
    • http://birkhoffhi.com/userfiles/files/34790348780.pdfIn PDF document text
    • http://avstralianature.ru/ckfinder/userfiles/files/90909782139.pdfIn PDF document text
    • http://futurepoolandspa.com/ckfinder/userfiles/files/30691574591.pdfIn PDF document text
    • https://www.tzounakos-insurance.gr/ckfinder/userfiles/files/84623393575.pdfIn PDF document text
    • http://drxzhang.com/userfiles/file/49104247334.pdfIn PDF document text
    • http://ct-tci.com/cttax/userfiles/files/96362883654.pdfIn PDF document text
    • http://tech-in.info/bramy/userfiles/file/jedusiritovigaxados.pdfIn PDF document text
    • http://jonme.net/ckupload/files/73078349169.pdfIn PDF document text
    • https://bliznacite.com/files/24419413251.pdfIn PDF document text
    • https://argekaucuk.com/nbg/upload/files/26013485302.pdfIn PDF document text
    • http://talk200.com/admin/admin/uploadfiles/file/45567811290.pdfIn PDF document text
    • http://tryinvest.eu/userfiles/files/53315904811.pdfIn PDF document text
    • http://www.lukoilmarine.com/ckfinder/userfiles/files/sorilufube.pdfIn PDF document text
    • https://universitecentrale.net/uploads/FCK_files/file/24949624616.pdfIn PDF document text
    • http://themadthinker.com/temp/vinney/HTML/userfiles/file/buruledikimexali.pdfIn PDF document text
    • http://adria-ex.com/images/blog/file/42930278151.pdfIn PDF document text
    • http://kazuma.ru/ckfinder/userfiles/files/47780744983.pdfIn PDF document text
    • http://www.farmaciavictoriayjmleon.com/userfiles/files/tigumizumebirogivezukow.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=phone+ringtone+apkPDF 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_off0000e18d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE18D 10412 bytes
SHA-256: 06ffc3706596b0905d9c0e58f9b0dcfa9b27dfd89c9a9ab3ae1e81e2e2c835c4
font_01_sfnt_off0000f910.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF910 17212 bytes
SHA-256: 47996fe0b73a723335c84dbb3a3ea8f58a647b8e466a942eae6427ecbc2e64b9
font_02_sfnt_off000125ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125AC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1