Malicious PDF — malware analysis report

Static analysis result for SHA-256 8197c78c62755a4a…

MALICIOUS

PDF

85.6 KB Created: 2021-08-11 01:50:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 78857379fcf89fe3d6a1343c0f7cc588 SHA-1: e0bc448c4b881ed2840ce53b2a7399027d07101a SHA-256: 8197c78c62755a4a9f7d819da2cec54bd93a72be9ba847013ff5ea19a5bed885
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by an ML classifier. It contains numerous embedded URLs, many of which point to compromised CMS uploads or are structured as link farms, suggesting an attempt to obscure the final destination or distribute malicious content. The presence of these link farms and the ML classification strongly indicate a malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://nikken-engineer.jp/export/sd205/www/jp/r/e/gmoserver/8/6/sd0748886/nikken-engineer.jp/fckeditor/upload/file/83015600726.pdf In PDF document text
    • http://www.elstar.ru/uploads/files/33393883769.pdfIn PDF document text
    • http://helderlive.nl/ckfinder/userfiles/files/59607403678.pdfIn PDF document text
    • https://creteservices.com/FCKeditor/userimages/file/gezibafugovonug.pdfIn PDF document text
    • http://thermogroup.ru/uploads/files/11574018144.pdfIn PDF document text
    • http://timelessmebel.ru/wp-content/plugins/super-forms/uploads/php/files/1191c86e619d230913200c78cd9169bc/12088335893.pdfIn PDF document text
    • https://sygimportaciones.com/wp-content/plugins/super-forms/uploads/php/files/nbmeik6q1q3ntnbbn7n15ac0ri/gujozunomuva.pdfIn PDF document text
    • http://goergenpainting.com/clients/0/0d/0d1038892961fdbf96b6a8e7e8daca8f/File/jusogabisokifirewe.pdfIn PDF document text
    • http://dgn89reunion.com/clients/862287/File/puvagividitazatom.pdfIn PDF document text
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f9b629121b---69020731346.pdfIn PDF document text
    • http://elturo.ru/img/upload/files/jijebepujotepenabizeja.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160be200bc3881---vebonujaxuvudisopakowob.pdfIn PDF document text
    • http://stacjaregeneracja.pl/userfiles/file/70387789112.pdfIn PDF document text
    • http://peaceinsrilanka.lk/userfiles/file/3371983182.pdfIn PDF document text
    • https://www.beadvised.co.uk/wp-content/plugins/super-forms/uploads/php/files/a7057ec1b4d6752800ea85a365a5a7bc/gejirofesokuto.pdfIn PDF document text
    • https://prestinieurope.com/userfiles/files/xunimudenedomuga.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/160d3e3fa614ef---61870323851.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/tms2jpqb6de2ce95n4if809kb6/6553288741.pdfIn PDF document text
    • http://omonetach.pl/foto/ilustracje/file/devipigemiwelokovijo.pdfIn PDF document text
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/16091a2949f268---8875625235.pdfIn PDF document text
    • http://arcenevents.nl/site/upload/files/69545176353.pdfIn PDF document text
    • http://taeguektour.com/FileData/ckfinder/files/20210604_B0463EF1E9F5CDF5.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607b38a4c0a61---56917666031.pdfIn PDF document text
    • http://www.lentilles-progressives.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1610039cc880ee---85709025384.pdfIn PDF document text
    • https://aduanaldelvalle.com/userfiles/file/bivebosudijigegugeno.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=canon+80d+battery+price+in+pakistanPDF 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_off0000e6b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6B2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fec9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEC9 11168 bytes
SHA-256: aaae594add0e908c682a7e63cf719b250f8d0c039d674e0d79ff178591720c28
font_02_sfnt_off000118e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118E1 17548 bytes
SHA-256: 4bc36c5527a18bc815630c267e64b3aa716f6ac08ff621ce3ee5ab6ec443f21d