Malicious PDF — malware analysis report

Static analysis result for SHA-256 4803a789326fbc39…

MALICIOUS

PDF

71.9 KB Created: 2021-09-17 07:11:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 98f58c013c3d2b5ab4ba79f7674ca5d9 SHA-1: dc17e0189f79c4dd6c88dcc18c7a40b6d659d9f3 SHA-256: 4803a789326fbc39d876a1791fc6b0785993b42202e6921c0fd415e712ccadae
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous external links, many pointing to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. The file's structure and link farm characteristics align with common techniques for initial access via malicious documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 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://noospc.ru/SITE/files/editor/file/17146510125.pdf In PDF document text
    • http://andrenickels.de/ckfinder/userfiles/files/letaxezegewaxisugikug.pdfIn PDF document text
    • https://akamercedes.com/images/uploads/files/kawemakibizipapamugokap.pdfIn PDF document text
    • http://casadiriposomarsala.it/userfiles/files/duduvowevuzubejupetamipi.pdfIn PDF document text
    • http://benrassam.com/uploads/files/tipimokom.pdfIn PDF document text
    • https://cissud.com/uploads/ck_editor/files/ximijefexen.pdfIn PDF document text
    • https://iagclaims.endataclaims.com/ModCoreFilesUploaded/file/somuzesizipewe.pdfIn PDF document text
    • http://ciarajewellery.com/editor_upload/file/zafapazozirozojoda.pdfIn PDF document text
    • https://eklyps.net/images/file/26678704972.pdfIn PDF document text
    • http://tctrack.vn/images/newtech/files/voroxizef.pdfIn PDF document text
    • https://aldapa.eus/files/galeria/files/jezatukumakezuzuz.pdfIn PDF document text
    • https://thegioibaobicarton.com/Images_upload/files/dejiginomagidisiware.pdfIn PDF document text
    • http://dagmare.de/userfiles/file/nepajilivi.pdfIn PDF document text
    • https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/r5unk9ienv38islpr0fib496lf/35707204664.pdfIn PDF document text
    • http://polyalpan.hu/_user/file/85792683018.pdfIn PDF document text
    • http://suachuaspa.com/upload/images-content/files/59722701360.pdfIn PDF document text
    • https://suprizpin.com/calisma2/files/uploads/17784251880.pdfIn PDF document text
    • http://wpklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/87466213908.pdfIn PDF document text
    • http://kimandyoo.com/userfiles/file/furanizametotedexal.pdfIn PDF document text
    • https://www.beewellrx.com/wp-content/plugins/super-forms/uploads/php/files/tmp/waleporisatak.pdfIn PDF document text
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137a6d604afe---botajumadibon.pdfIn PDF document text
    • https://dnsbp.com/all4help/fckuserfiles/file/29090870304.pdfIn PDF document text
    • http://www.aceitunasdelguadalhorce.es/ckfinder/userfiles/files/kopobukekepijikixonuxex.pdfIn PDF document text
    • https://www.aifimm.it/admin/inc/ckfinder/userfiles/files/rataxavuxalefalivalelatek.pdfIn PDF document text
    • http://geoodwierty.pl/files/file/fojekutufiduneko.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=app+icon+notification+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_off0000b8ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8EE 16216 bytes
SHA-256: baa11176448a49e64ecd0cdd902982e0ea2a7dee8906d8c3b5b171bd1f5f48be
font_01_sfnt_off0000e28d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE28D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000faa4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAA4 10248 bytes
SHA-256: 5a09f37f8677343aa711f456e8d5161f913d4ed68a8295a5755ddc9aaa20034e