Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a381cbb2c33ace2…

MALICIOUS

PDF

91.3 KB Created: 2021-09-13 04:10:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 18df5602dd55f3026f62102412abf036 SHA-1: aa019b0913b624c80e819d3128c6ff50cebb0c4f SHA-256: 8a381cbb2c33ace2c023cd5dd0358cdac3915ffddcd0e37b5aa8137a1b2e8c09
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to other PDF files hosted on various domains, indicating a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests this malicious intent. While no scripts were explicitly extracted, the presence of embedded URLs and the ML classifier's high confidence score point towards a phishing or malware distribution scheme, likely delivered via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://air-ned.com/uploads/files/zesofotexuvuxajog.pdf In PDF document text
    • http://fluitec.fr/ressource/site-image/files/31036826406.pdfIn PDF document text
    • https://brukspec.pl/upload/file/zetolalebisaguvujib.pdfIn PDF document text
    • https://clubkdo.fr/img/pics/files/jafekopukuvikoturatu.pdfIn PDF document text
    • https://malmospelmanslag.se/userfiles/file/39683043971.pdfIn PDF document text
    • https://egc.ecrom.work/syo/files/zapizunagavuruf.pdfIn PDF document text
    • http://musik-fachberatung-neumarkt.de/images/uploadedimages/file/kaxawolofukeri.pdfIn PDF document text
    • https://maturana.cl/upload/file/xinolado.pdfIn PDF document text
    • https://tybistanbul.org/resimler/files/29445471281.pdfIn PDF document text
    • http://bburago.info/admin/fckeditor/userfiles/file/22860323820.pdfIn PDF document text
    • http://www.rupankar.com/fckimages/file/41032232816.pdfIn PDF document text
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/5536aa773ff3431cb6e0a524fde38742/25731957532.pdfIn PDF document text
    • http://msnladyboy.com/ckfinder/userfiles/files/13260099461.pdfIn PDF document text
    • https://www.vita-organic.eu/admin/ckfinder/userfiles/files/30776615355.pdfIn PDF document text
    • http://holmeslawfirm-iowa.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/rajiduzatenosomab.pdfIn PDF document text
    • http://opuspointpartners.com/ckfinder/userfiles/files/jivimukapotuteten.pdfIn PDF document text
    • https://galaxytraining.examinationonline.com/files/79878584260.pdfIn PDF document text
    • https://radekslodkiewicz.pl/files/file/komotalofizerejov.pdfIn PDF document text
    • https://aqua2go.pl/galeria/file/nopozitijonisope.pdfIn PDF document text
    • http://k9careclinic.in/ckeditor/ckfinder/userfiles/files/88531576464.pdfIn PDF document text
    • http://bularz-auto.pl/images/userfiles/file/lewovoxoxibovaweta.pdfIn PDF document text
    • http://halongwave.com/userfiles/file/85247161459.pdfIn PDF document text
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/f066f138a472c7ae6f31c452ed36191b/kugurutibufutafuf.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=adb+screenrecord+commandPDF 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_off0000fdfe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDFE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011615.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11615 10416 bytes
SHA-256: 36e90a8500c303fed81a89adb264dbd5d28bd705a68b05f5bca296874cc2afa8
font_02_sfnt_off00012da1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DA1 18832 bytes
SHA-256: 10d7095ffca10ddb4163701494804f68560a15bfc40a6903668ee39c929bdc1d