Malicious PDF — malware analysis report

Static analysis result for SHA-256 e8f73e2720ec1b57…

MALICIOUS

PDF

76.5 KB Created: 2021-09-19 06:18:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 84328cb511690bb714c1a3385061e3fd SHA-1: e973afe67676713a8495d365db8a05f82fb12f9a SHA-256: e8f73e2720ec1b57d449b31011f595a25247978983ca564648d2ffe40ba5d4cc
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with several URLs pointing to compromised CMS upload directories and disposable hosting, suggesting a phishing or malware distribution scheme. No scripts were extracted, and the document body was unreadable binary data, but the presence of numerous external links is the primary indicator of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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 https://menu2uplus.com/images/file/xezobadodiroje.pdf In PDF document text
    • https://sanagustin.cl/files/nulurapuvulevirunoni.pdfIn PDF document text
    • https://www.studioline.ie/ckfinder/userfiles/files/59111224648.pdfIn PDF document text
    • http://mu-rrrc.com/userfiles/file/guloteponivur.pdfIn PDF document text
    • http://fourfoods.com/images/files/85810933453.pdfIn PDF document text
    • http://johnmichaelharrisonlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/61893323173.pdfIn PDF document text
    • https://rajatotogroup4.com/contents/files/66374460981.pdfIn PDF document text
    • http://fohow77.ru/upload/file/kawafotimuwiludamibu.pdfIn PDF document text
    • http://monkey-do.net/userfiles/file/82731808100.pdfIn PDF document text
    • http://cuacongtudongbinhduong.com/upload/files/radodowijerusezoxigibefe.pdfIn PDF document text
    • https://hotelristorantenovecento.it/wp-content/plugins/super-forms/uploads/php/files/1c032baeaed6606a23e7f308eb86a6ba/37292587414.pdfIn PDF document text
    • https://koratspring.com/upload/file/rizofokosupa.pdfIn PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/16133c252d69a9---gudufuwurododegus.pdfIn PDF document text
    • https://erdemlerkoleji.com/resimler/files/jexemove.pdfIn PDF document text
    • http://divapharma.com/uploaded/file/piponuxajilijevesed.pdfIn PDF document text
    • http://solarissoft.com/img/userfiles/files/98992987762.pdfIn PDF document text
    • http://ecme.site/2015/vat/upload/files/5503119529.pdfIn PDF document text
    • http://urjabatteries.in/userfiles/file/15382911560.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141efb2f0fa2---98538661002.pdfIn PDF document text
    • http://aspbae.org/userfiles/file/16590832542.pdfIn PDF document text
    • http://capableapp.com/uploads/files/7821200726.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=yugioh+online+apkPDF 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_off0000c9b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9B3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e1ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1CA 10340 bytes
SHA-256: da8bd880d493db64613b583b2df63377ec006ea90ca3a8a92627b890623dbc2b
font_02_sfnt_off0000f8f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8F8 17024 bytes
SHA-256: cbea96717e11839ed63b77a796c78295533625c33fea76f285407ef700ee8e7e