Malicious PDF — malware analysis report

Static analysis result for SHA-256 2fb8d3416cd3cdfd…

MALICIOUS

PDF

85.5 KB Created: 2021-09-21 21:31:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: d4148579faa5a9f492484ce58068a039 SHA-1: bcebe63e71ad4cf3fa1498113755b66c8e8449a8 SHA-256: 2fb8d3416cd3cdfd8e931cf3025945b86b4b4af07988d7b611339478de77497f
166 Risk Score

Malware Insights

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

The PDF contains multiple heuristics indicating malicious intent, including random and disposable link farm URLs, and is flagged by a machine learning classifier and ClamAV as a phishing trojan. The document body is heavily obfuscated, but the presence of external links suggests an attempt to redirect the user to a malicious payload, likely a second-stage PDF or executable. No scripts were extracted, but the PDF structure itself is used to host malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://nazycakes.com/userfiles/file/toguduniwesamelim.pdf In PDF document text
    • https://medsplus.us/admin/images/file/moribopasoku.pdfIn PDF document text
    • https://at-studio.tw/app/webroot/userfiles/files/20210910_104724.pdfIn PDF document text
    • http://nomayaku.com/userfiles/file/peleguzaz.pdfIn PDF document text
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/93babc33159e4281e109965398f1250f/36291032175.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145c48e88910---rovolozufiforumuwaxe.pdfIn PDF document text
    • http://desiaussies.com/ckeditor/uploads/files/70847008327.pdfIn PDF document text
    • http://eiak.org/upload/editor/files/21112817726.pdfIn PDF document text
    • https://tectrongim.com/uploads/files/bupamivagijotirof.pdfIn PDF document text
    • https://samngaimarble.com/html_upload/file/748635664.pdfIn PDF document text
    • http://whuntex.ru/userfiles/file/26740454876.pdfIn PDF document text
    • https://rdw-wolf.de/backend/ckfinder/userfiles/files/biriduburuzimebujupakud.pdfIn PDF document text
    • https://defi128.phpascal.com/userfiles/files/85243512048.pdfIn PDF document text
    • https://deitratech.com/userfiles/file/lepegubixe.pdfIn PDF document text
    • http://xprchemical.com/upload/files/wanogalinobimoxosijipadi.pdfIn PDF document text
    • http://bandenplaats.nl/cmsimages/file/43445710081.pdfIn PDF document text
    • http://yourtruck.be/upload/ckeditor/file/pebazufizolumi.pdfIn PDF document text
    • https://ustunbilgisayar.com/userfiles/files/30605267968.pdfIn PDF document text
    • http://gdfsztal.com/uploadfile/files/ginukobunuzidizetejibuwol.pdfIn PDF document text
    • http://aqcorth.specialty-match.com/upload/files/jebapaxobidemavamabejiz.pdfIn PDF document text
    • http://carraracucinecomponibilitrapani.it/userfiles/files/binipomelaxuzalazuba.pdfIn PDF document text
    • http://status-go.net/gfx/userfiles/files/kofurajipovotileraf.pdfIn PDF document text
    • http://artio.pl/files/files/35809603284.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=clash+royale+apk+androidPDF 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_off0000e73f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE73F 10628 bytes
SHA-256: 5f37356ad6c35a52b3e9fbaf330b172dc83934f18f783707b431a878751ec43a
font_01_sfnt_off0000ff79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF79 18592 bytes
SHA-256: af3bbed9efbd76d4088e6ae6df3ba671529f718500522e45311e2ea47f2745ec
font_02_sfnt_off00013062.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13062 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1