Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6c79d969ca10c3a…

MALICIOUS

PDF

76.4 KB Created: 2021-09-18 14:02:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 37e6cf31e1e8f8451e11fcdaaf8d6382 SHA-1: fc37d11231d2dc16cbac452c8a82cf29369bc2d4 SHA-256: a6c79d969ca10c3a189ac46185c33b03ba8b756e79f007bfa6e2d8bdeef79618
166 Risk Score

Malware Insights

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

The PDF contains multiple heuristics indicating it is a link farm designed to redirect users to malicious content, specifically other PDF files hosted on disposable domains. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were directly extracted, the PDF's structure and numerous external links point towards a phishing attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://queure.ru/uplcv?utm_term=xhtml+to+pdf+online PDF link annotation
    • http://zulassungsservice4you.de/bilder/file/97300080500.pdfIn PDF document text
    • https://jeevandeepspecialcare.com/ckeditor/ckfinder/userfiles/files/sodakukirat.pdfIn PDF document text
    • http://asude.istanbul/ck_images/files/58800313828.pdfIn PDF document text
    • https://minlinart.com/archive/upload/files/77985192429.pdfIn PDF document text
    • http://weighlessthisyear.com/ckfinder/userfiles/files/jusomopuvaxiloko.pdfIn PDF document text
    • http://agrostroi-proekt.ru/ckfinder/userfiles/files/13141727071.pdfIn PDF document text
    • http://vinhosnorte.com/images/files/kononetadezonokuravu.pdfIn PDF document text
    • https://christianklein.eu/Quansis/ckfinder/userfiles/files/pisubeliramugaviwopasivix.pdfIn PDF document text
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/16141995c0de3d---1755876834.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/19387701694.pdfIn PDF document text
    • https://vilus.cz/userfiles/file/50010891807.pdfIn PDF document text
    • http://refah4ter.info/basefile/hotelrefah4terir/files/60948816595.pdfIn PDF document text
    • http://ambulatorioveterinarioscapindandrea.it/userfiles/files/pimewo.pdfIn PDF document text
    • https://thietkewebseo.com/webroot/img/files/38404678997.pdfIn PDF document text
    • https://hpx.com.ua/wp-content/plugins/super-forms/uploads/php/files/90024564231713c8a9e5d0338c63d183/xiweg.pdfIn PDF document text
    • https://petribax.com/userfiles/file/49580895425.pdfIn PDF document text
    • https://eghamatsafar.ir/basefile/eghamatsafar/files/motitedopawoziv.pdfIn PDF document text
    • http://design-klasse.de/ckfinder/userfiles/files/84631312901.pdfIn PDF document text
    • https://flavio-tonon.it/public/file/5258745563.pdfIn PDF document text
    • https://zzwgjx.com/d/files/87836121247.pdfIn PDF document text
    • http://joomlacode.org/fckeditor/editor/filemanager/img.php?file=file/woneweluwet.pdfIn PDF document text
    • http://geoman.cz/data/file/nimatafozakugotivux.pdfIn PDF document text
    • https://srccaa.bdbabymart.com/app/webroot/ckfinder/userfiles/files/42653080622.pdfIn PDF document text
    • http://p-energo.ru/content/file/57341034031.pdfIn PDF document text
    • 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_off0000c882.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC882 10340 bytes
SHA-256: 9edca0449d5ade2369523e340102afa96e3882c53bfc1be874ddef837322e365
font_01_sfnt_off0000df93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF93 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f7a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7A5 16984 bytes
SHA-256: 8160f37b82597b546028d8ed361b556d0186e2321702c8b5e790b4ddfa9007bb