Malicious PDF — malware analysis report

Static analysis result for SHA-256 c9cc1984f281a6c4…

MALICIOUS

PDF

73.6 KB Created: 2021-10-03 21:13:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: a3f9edc70e8efa5317047bb0b135d5e9 SHA-1: 9217ca30797e0949c0a979d3cbb14f5723e39cc8 SHA-256: c9cc1984f281a6c41f0b102eaa41a22cfcefb710059815510b4d70d9aafdc1d6
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm pointing to numerous domains, several of which are hosted on compromised CMS upload storage and disposable hosting. The ML classifier strongly indicated maliciousness. The presence of multiple external URIs and link farm heuristics suggests the primary purpose is to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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 http://sapthagireesyathra.com/userfiles/file/61395316211.pdf In PDF document text
    • http://xnucleus.com/members/member_images/files/zogatalulamegivasev.pdfIn PDF document text
    • https://premiersuli.hu/files/files/mexazezukufed.pdfIn PDF document text
    • http://labradory.pl/file/70505153026.pdfIn PDF document text
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/161450c6a48ed5---sisuwumotiweba.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/3eoevpmf4r37b0fkf389ucdau4/12906555809.pdfIn PDF document text
    • http://greentreeprep.com/cote_dor_import/admin/ckfinder/userfiles/files/rujokixagakoduxiv.pdfIn PDF document text
    • http://richmore.kr/uploadfile/fckeditor/file/20739898383.pdfIn PDF document text
    • http://jawarakreasi.com/file/99130482047.pdfIn PDF document text
    • https://bda.ch/ckfinder/userfiles/files/17971148901.pdfIn PDF document text
    • http://wadsoda.com/UserFiles/File/kofamuvukim.pdfIn PDF document text
    • http://hicoweld.com/shop/fck_file/file/puxemotefida.pdfIn PDF document text
    • https://mobilaide.com/upload/editor/file/31697540882.pdfIn PDF document text
    • http://gyndoktors.de/ckfinder/userfiles/files/574041088.pdfIn PDF document text
    • http://unternehmensberatung-hegenbarth.de/userfiles/file/30372582844.pdfIn PDF document text
    • http://penzion.sarmo.cz/Images/file/kumizosopifisixejum.pdfIn PDF document text
    • http://windowsplusllc.com/ckfinder/userfiles/files/jojefojuguvimupimo.pdfIn PDF document text
    • http://mail.me.ntou.edu.tw/ckfinder/userfiles/files/20210915_140016.pdfIn PDF document text
    • http://kmbb.at/userfiles/file/18393819549.pdfIn PDF document text
    • http://minhanh.com/files/37995751682.pdfIn PDF document text
    • https://samavetpharm.com/userfiles/files/suzamiluzojir.pdfIn PDF document text
    • https://anpheatingandac.com/nbloom/fckuploads/file/85636123396.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614e4e136b0ec---fisexonetijos.pdfIn PDF document text
    • http://slhospital.com/upload/fckeditor/file/tutowulopibevowifodok.pdfIn PDF document text
    • https://textosolutionslinguistiques.com/upload/editor/file/mevowivugogedugusix.pdfIn PDF document text
    • http://www.offshoreyachts.net/web_upload/editor/files/nerebotaso.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/16159d60973ac1---vukura.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=exagear+obb+downloadPDF 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_off0000b8b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8B0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d0c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0C2 18724 bytes
SHA-256: da1846e550d526c43437e231a13e9d17be24f168930590b2f49e9bd0bd43fc41
font_02_sfnt_off000100fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100FA 10376 bytes
SHA-256: 610cefa5997e0160cc8760c77dc6b5c5ca4f46edcc2855546d8b8ba1dc83c6e6