Malicious PDF — malware analysis report

Static analysis result for SHA-256 0b4ab5b534986ec0…

MALICIOUS

PDF

95.3 KB Created: 2021-09-17 15:52:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 719d4816aa1bea9d1b903c713f37e488 SHA-1: af96ff7bb40d5815a7917bff666205810598f18a SHA-256: 0b4ab5b534986ec0fd711724c8ae5142176a47fa7ce098611cd909c54e1e6edb
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with several URLs pointing to compromised WordPress uploads and other disposable hosting. The document body is unreadable binary data, suggesting it is not intended for direct user consumption but rather to host malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://gartenbaukoeln.de/uploads/files/mijajemevepazowejukeliwij.pdf In PDF document text
    • https://tcremich.lu/files/files/38147615103.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613bc762741e8---67886729511.pdfIn PDF document text
    • https://lederstuehle-shop.de/ckfinder/userfiles/files/67302735956.pdfIn PDF document text
    • http://dmhu.eu/uploads/uplib/file/separaviterolanukari.pdfIn PDF document text
    • http://salukool.ee/upload/userfiles/file/45536090064.pdfIn PDF document text
    • http://dierenwinkelindex.nl/images/uploads/20271877831.pdfIn PDF document text
    • https://ce-mi.pl/uploads/userfiles/files/sopigufirorive.pdfIn PDF document text
    • https://zoldlaptop.hu/ckfinder/userfiles/files/bipunatewonalegiga.pdfIn PDF document text
    • http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c84cc0c632---46271413115.pdfIn PDF document text
    • http://ap116.ru/userfiles/file/papuxig.pdfIn PDF document text
    • http://amsuatrust.org/survey/userfiles/files/tizarejavilavuxatofina.pdfIn PDF document text
    • http://penetrat.ru/files/files/54837052042.pdfIn PDF document text
    • http://cosmosimpex.com/app/webroot/ckfinder/userfiles/files/zemunowefudizuruwopub.pdfIn PDF document text
    • http://picassogift.com/Uploadfiles/files/19268514892.pdfIn PDF document text
    • https://kipass.fr/userfiles/file/81065279944.pdfIn PDF document text
    • http://arisutour.com/ckupload/files/lawanig.pdfIn PDF document text
    • http://tries.cz/media/images/upload/file/97334581857.pdfIn PDF document text
    • http://ajisushionline.com/uploads/files/sinuvuxudir.pdfIn PDF document text
    • https://staffxrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/0048b933e83022c4addabb07b7a485cd/duzazojiwilajuranukatepeb.pdfIn PDF document text
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/e7adf69eb415e4707f46016902f6a9e2/kozari.pdfIn PDF document text
    • http://kroonzuivel.nl/ckfinder/userfiles/files/42614190774.pdfIn PDF document text
    • https://ixiu-23.com/uploads/files/202109070602128289.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613e9f960a772---gezufulavotegisewirif.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=android+opengl+matrixPDF 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_off00010f95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F95 10652 bytes
SHA-256: 8ca6b978c0445227741523eec2154c0ecf29043ac17cba0e7c1568aca6b06fe4
font_01_sfnt_off000127b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127B5 18032 bytes
SHA-256: 3b95c3309d9744092c51798f9af88adc892bf85dd8ae67aed08b767041601a54
font_02_sfnt_off00015776.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15776 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1