Malicious PDF — malware analysis report

Static analysis result for SHA-256 2dc9c8c260cf269a…

MALICIOUS

PDF

71.3 KB Created: 2021-08-26 10:28:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 2d41debc8ba538415fa0e4900aaae5a7 SHA-1: 8804e7badc57c2b142b852b4dff389e80796ec84 SHA-256: 2dc9c8c260cf269a527cf45cd51f765514a18db0355961e151cad26a1ab66618
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous distinct hosts, many of which are hosted on compromised CMS upload directories. The ML classifier strongly indicates maliciousness, and the structure suggests the document is designed to lead users to external, potentially malicious, content. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b6f306dfd4a---dusewimotasokelimo.pdf In PDF document text
    • https://thucphamtruongxanh.com/Upload/files/bezud.pdfIn PDF document text
    • http://pataibicaj.hu/userfiles/file/petalidakimowuvitavo.pdfIn PDF document text
    • https://anmimar.com/royal/userfiles/file/97331863447.pdfIn PDF document text
    • http://naturallabs.de/userfiles/file/68378481169.pdfIn PDF document text
    • https://sunnyvale.com/wysiwygfiles/file/paromamiwizebewel.pdfIn PDF document text
    • https://hyundaia.ru/userfiles/file/4191462728.pdfIn PDF document text
    • http://webinaris.org/ckfinder/userfiles/publics/files/1459903601.pdfIn PDF document text
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cdf52c8155---bagamatokevaxijufexuro.pdfIn PDF document text
    • https://www.urban-quartz.co.uk/wp-content/plugins/super-forms/uploads/php/files/75105516d88db63b31c3ad48f40ec737/lumakazijejifafowab.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/965d8181d298006a450a96666ac41381/31598975487.pdfIn PDF document text
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/c071aecad6f1cce424af417f6d314ec7/tokegeguje.pdfIn PDF document text
    • http://sciencevier.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ee883fcdead---87134001533.pdfIn PDF document text
    • http://wallsfamilyreunion.com/clients/876683/File/xenegogaxetezufavaxu.pdfIn PDF document text
    • http://feuerwehr-mittenwalde.de/mediathek/files/lazuliwow.pdfIn PDF document text
    • http://nensi.si/upload/file/57165182925.pdfIn PDF document text
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0e9927eb33---ligesirusobepuzinasegumoj.pdfIn PDF document text
    • http://mellorymotors.ru/admin/ckfinder/userfiles/files/tetememofoto.pdfIn PDF document text
    • http://pp-aqua.com/userfiles/files/42979110068.pdfIn PDF document text
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c07219d69f---39801311724.pdfIn PDF document text
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083f820049d7---fakizivad.pdfIn PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/160bb508f18a22---85617659938.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=lincoln+park+greeleyPDF 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_off0000b79d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB79D 10444 bytes
SHA-256: 750214f6210c74c348dfc7d288ece74c10e2bee1610167e758227c46763be217
font_01_sfnt_off0000cf64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF64 15860 bytes
SHA-256: a86a256f86343daaeffc6c23802c7fad7ce8a111a5f423014efd8d8e34eae7f4
font_02_sfnt_off0000f83e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF83E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1