Malicious PDF — malware analysis report

Static analysis result for SHA-256 41da76c75012b078…

MALICIOUS

PDF

73.8 KB Created: 2021-08-28 12:00:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 3d6584d9852ade0f07be7c4590ee53e1 SHA-1: adaf1b2e7dd8235afd52ff1af7e7a91a7792f4b8 SHA-256: 41da76c75012b078a8243819b9bb9434dcd239ccb17c56f6a595dadf46b8afef
96 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to other PDF files hosted on potentially compromised websites or disposable domains. The ML classifier strongly indicated maliciousness, and the link farm behavior suggests an attempt to manipulate search engine results or distribute further malicious content. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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 https://uniqrelation.com/userfiles/file/kuwirekunidisijinuxunu.pdf In PDF document text
    • http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/16127d89080b56---xabujolukixexaxilepen.pdfIn PDF document text
    • https://shinyjewellers.com/wp-content/plugins/super-forms/uploads/php/files/uc186oadomktfdndt66vt61sef/7084151019.pdfIn PDF document text
    • http://gamax-motor.cz/data/dokumenty/tujufunut.pdfIn PDF document text
    • https://baoyi-chuck.com/ckfinder/userfiles/files/zagonek.pdfIn PDF document text
    • https://brawlcall.com/ckfinder/userfiles/files/dotakuti.pdfIn PDF document text
    • https://teenvolunteer.org/wp-content/plugins/super-forms/uploads/php/files/4862e1d71ed7cf1140b3ae6ebcb7f6c8/88128726731.pdfIn PDF document text
    • http://cpgny.com/userfiles/files/gijuzinutij.pdfIn PDF document text
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1606f580f146f4---binovivumiputerovisimolu.pdfIn PDF document text
    • http://theaterbuehne-schwandorf.de/userfiles/file/gidanarewi.pdfIn PDF document text
    • http://amicalelaique-guyancourt.fr/ckfinder/userfiles/files/kutufebonexilixenusi.pdfIn PDF document text
    • https://olgapopovaphoto.com/wp-content/plugins/super-forms/uploads/php/files/11074f789118ba861601d0201b04cebf/25453987505.pdfIn PDF document text
    • http://woodwork.pl/ubezpiecz/obrazy/file/651187164.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210730014606.pdfIn PDF document text
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ed0213bc04---buromevasif.pdfIn PDF document text
    • http://hydrem.ru/images/file/jimixod.pdfIn PDF document text
    • https://autotrilogy.com/wp-content/plugins/super-forms/uploads/php/files/b29c58d122855d65926d53d61351d07a/kemetarasupuvenuxuva.pdfIn PDF document text
    • http://beergolfers.com/blog/images/file/48487841420.pdfIn PDF document text
    • http://precisao.org/files/files/xamogivozab.pdfIn PDF document text
    • http://inewbus.com/wp-content/plugins/super-forms/uploads/php/files/lho1cfcfoamj04cvsfpo6ihk43/zogelexexubotimakapokap.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/160788e5e915ee---gufiretenedodidotuxa.pdfIn PDF document text
    • http://geofer.eu/userfiles/files/rurojoka.pdfIn PDF document text
    • http://www.dkmodels.net/ckfinder/userfiles/files/warijirejumawomotutuvukan.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=5ps+of+marketingPDF 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_off0000bf21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF21 16268 bytes
SHA-256: da00f4f838522623cc158ffd405d6b31a297e421609066dbf006a30fb281b363
font_01_sfnt_off0000e883.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE883 10784 bytes
SHA-256: 5c3dc4b6db6e21b83a781d9dc63fde1616e6009cacd78499b41cdd9ac99ba09f
font_02_sfnt_off00010165.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10165 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1