Malicious PDF — malware analysis report

Static analysis result for SHA-256 d65dbb55ac2a9d68…

MALICIOUS

PDF

85.5 KB Created: 2021-09-13 07:48:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: cce6ef4a2819c553f7939ec39fe67c75 SHA-1: 630ccedc7fdf4ca139e754a57420c0bbfb128d1f SHA-256: d65dbb55ac2a9d683b29e92e571dea3444f28d018c5f4ce1fdcab197dbc3b19f
126 Risk Score

Malware Insights

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

The sample was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous embedded URLs pointing to external PDF files, with one heuristic identifying it as a link farm on disposable hosting. The primary attack pattern involves directing users to these external malicious PDFs, likely for phishing or to deliver further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://autoscuolapezzano.it/userfiles/files/79753862577.pdf In PDF document text
    • https://bienenaktuell.com/sites/bienenaktuell.com/files/file/xafozulupefifigifoz.pdfIn PDF document text
    • https://anne-berger.de/sites/anne-berger.de/files/fkcfile/81332654269.pdfIn PDF document text
    • http://philipwillettelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/43107353588.pdfIn PDF document text
    • https://profipreklady.cz/www/ckfinder/userfiles/files/jonazatok.pdfIn PDF document text
    • http://influences-vegetales.eu/assets/Image/files/29974437120.pdfIn PDF document text
    • http://master-stroi76.ru/userfiles/file/faritomexodezodafawuboma.pdfIn PDF document text
    • http://exdebt.bg/userfiles/file/31548054362.pdfIn PDF document text
    • https://gotoko.com/cmsv2/upload/files/wunukaruxajemasovux.pdfIn PDF document text
    • https://sluganarodu.org/userfiles/files/mokexadavovadidamen.pdfIn PDF document text
    • http://statsale.com/data/upload/ck/files/91989336557.pdfIn PDF document text
    • https://maribon.net/app/webroot/files/userfiles/files/giravidigalutujefolubi.pdfIn PDF document text
    • http://savitaco.com/uploads/images/files/21832952183.pdfIn PDF document text
    • http://yaqeen-eg.com/userfiles/file/wawonemimuk.pdfIn PDF document text
    • https://zahidnawaz.com/UploadedImages/image/xijaregaxodug.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138d896bb014---45098313212.pdfIn PDF document text
    • https://pratham.one/file/bukam.pdfIn PDF document text
    • https://sportnazona.bg/f/uploads/files/penamaga.pdfIn PDF document text
    • https://saksisan.com/upload/ckfinder/files/93276911812.pdfIn PDF document text
    • http://hanauhrova.cz/files/60670083703.pdfIn PDF document text
    • http://www.jasfec.com/imgs/uploads/lidizubatojuputozodiguvi.pdfIn PDF document text
    • http://ilink.pl/userfiles/file/57611167252.pdfIn PDF document text
    • https://alebusph.centralcms.cloud/galeria/files/67100512010.pdfIn PDF document text
    • http://www.anieliasfx.com/uploads/textareas/file/jupanazovuzexidu.pdfIn PDF document text
    • http://lexprikson.com/admin/style/images/userfiles/file/72021275673.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=3+functions+of+the+muscular+systemPDF 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_off0000e9a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9A7 17580 bytes
SHA-256: 7c53aebc34533699161722f7711399ce8c8a2b8af331372b4e7aded53d76c0fe
font_01_sfnt_off000116c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116C4 10892 bytes
SHA-256: 817b8519f888aaa7515e46db054b7681b6769e23bc1a950115888928c07c6915
font_02_sfnt_off00012fcf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12FCF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1