Malicious PDF — malware analysis report

Static analysis result for SHA-256 a64d6394125c8332…

MALICIOUS

PDF

69.5 KB Created: 2021-09-28 06:08:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: cab1509eb75bf08c6df0049998848066 SHA-1: b32330b4eaee264e23a4e36b45dcb390da081494 SHA-256: a64d6394125c8332379b1a6aff4cfd9fe89c36d79ad7c289f1e73543516f63bf
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm. It contains numerous URLs pointing to other PDF files, many hosted on potentially compromised WordPress sites or disposable domains. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a deliberate attempt to manipulate search engine rankings or distribute malicious content through a network of links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://brixtontaxi.com/survey/userfiles/files/buxis.pdf In PDF document text
    • http://leinerpakgelatine.com/survey/userfiles/files/1717394542.pdfIn PDF document text
    • https://digireg.ru/upload/xejawisofaros.pdfIn PDF document text
    • http://vedepcuaem.com/luutru/files/41082500861.pdfIn PDF document text
    • https://aftaplan.com/works/peepsparty/html/upload_files/file/15104180419.pdfIn PDF document text
    • http://elcolono.net/userfiles/files/xideruvizike.pdfIn PDF document text
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/1612f37f74756b---matasumevorazirib.pdfIn PDF document text
    • https://alaskaproauto.net/nbloom/fckuploads/file/widodanodigiropixo.pdfIn PDF document text
    • http://archetipoingegneria.it/userfiles/files/13670213359.pdfIn PDF document text
    • http://agedwedfjtj.pretty-match.com/upload/files/79103846667.pdfIn PDF document text
    • http://nissanotogovap.vn/uploads/images/files/dafirelu.pdfIn PDF document text
    • http://www.mousumibanerjee.com/fckimages/file/27699110681.pdfIn PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/1614d16b041de2---65980236630.pdfIn PDF document text
    • http://shamayachts.com/upload/file/tusase.pdfIn PDF document text
    • https://sainaudit.mn/File/konogexir.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/1615087ec57f3e---silasamalafudore.pdfIn PDF document text
    • http://clarksville.net/wysiwygfiles/file/kenapifajewosed.pdfIn PDF document text
    • http://jaluzipro.ru/public/userfiles/file/gasawimuzu.pdfIn PDF document text
    • http://www.neoneofitou.com/ckfinder/userfiles/files/44790233521.pdfIn PDF document text
    • http://twapp.freshkon.com/upload/files/rorigilisemafekadafezesu.pdfIn PDF document text
    • https://oferta.lt/i/File/salow.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=how+to+change+refresh+rate+in+redmi+note+7+proPDF link annotation
    • https://tes-sys.com/uploads/ckfinder/files/20210904/16307273705824.pdfIn PDF document text
    • 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_off0000b110.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB110 14664 bytes
SHA-256: 634a7e7fddb2287b4d731bf4da832ba0644a7435a5ec0fc2d665285c0263d7a1
font_01_sfnt_off0000d643.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD643 11148 bytes
SHA-256: d5f51c722761b9719a690bf30bda322e3c3857571221c2ed290d67f90ab337c4
font_02_sfnt_off0000f003.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF003 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1