Malicious PDF — malware analysis report

Static analysis result for SHA-256 2262db0d78d8b871…

MALICIOUS

PDF

87.2 KB Created: 2021-09-10 13:34:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: bd3312e77cc70c9a180ee76ba86870b2 SHA-1: dab3d8f250bbb24f53c7cc55334294bdd7aa16a0 SHA-256: 2262db0d78d8b87176bf7e8a55a23cfcb11697b8b09ed7071f0ed8e46ee81c61
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV and an ML classifier as malicious. It contains numerous embedded URLs, many of which point to PDF files hosted on various domains, suggesting a link farm or redirection mechanism. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM indicates a pattern of using disposable hosting for these links. While no scripts were explicitly extracted, the presence of external URIs and the overall structure point towards a phishing or malware distribution attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://shortguycentral.com/ck_uploads/files/visigubiginivoleduluji.pdf In PDF document text
    • http://mercuresamuichaweng.com/admin/file/saziduferofenon.pdfIn PDF document text
    • http://saveondealz.com/ckeditor/ckfinder/core/connector/php/uploads/files/rejuganowonen.pdfIn PDF document text
    • https://cvconstructionsgoa.com/pharma/admin/userfiles/file/48742621120.pdfIn PDF document text
    • http://leprofit.ee/cmsfile/contentfiles/jujififulanatojafejolamus.pdfIn PDF document text
    • https://poulinstrapscan.com/userfiles/file/xalixikila.pdfIn PDF document text
    • https://e-room.co/userfiles/file/55600859556.pdfIn PDF document text
    • http://dekogard.net/deko/veri/_files/32562881266.pdfIn PDF document text
    • https://lalicorne-hotel.com/userfiles/file/nuwefijaxuvixixofi.pdfIn PDF document text
    • http://gammatradings.com/userfiles/file/konisemejibisapajofekeler.pdfIn PDF document text
    • https://people11people.com/uploads/File/dujonewevuzelubikanatev.pdfIn PDF document text
    • https://www.tahitotfaluovodak.hu/ckfinder/userfiles/files/gufadevavanev.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16130fd8eb5f9f---39663374278.pdfIn PDF document text
    • https://gruntbudowa.pl/files/file/70928405449.pdfIn PDF document text
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/a35f301052a26c942e4719d935ef1110/24481621254.pdfIn PDF document text
    • https://receptabc.hu/images_banner/files/wisinufovutidefu.pdfIn PDF document text
    • http://xn--80aafkatcapceshpicpg3h.xn--p1ai/pict/file/vosofuzexavisavovufo.pdfIn PDF document text
    • https://traffictkt.com/viking1/uploads/files/wufurobepereziz.pdfIn PDF document text
    • https://5uempat.com/contents/files/nilikitavavilusizodivufeb.pdfIn PDF document text
    • http://icbiz.ru/userfiles/file/55664026674.pdfIn PDF document text
    • http://hainfelderteich.at/38393718540.pdfIn PDF document text
    • https://cplastik.eu/data/cms/file/borexegalaxifosexom.pdfIn PDF document text
    • https://ofly.om-digitalsolutions.cn/upload/files/lizapav.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=hbo+max+on+firestick+downloaderPDF 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_off0000ebbd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBBD 19140 bytes
SHA-256: 36e80128c27d0b7c8ff46b2749b007f22ca30d234e01e474c72b1e6d37a82215
font_01_sfnt_off00011d6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D6B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013582.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13582 11048 bytes
SHA-256: 3e6d45eaf430ad3500044a9f49323fca6a51bd769ad02ace1e71b6eb40f3c085