Malicious PDF — malware analysis report

Static analysis result for SHA-256 3bde3a1491d0c992…

MALICIOUS

PDF

105.7 KB Created: 2021-09-07 06:28:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 4a0b932ae4fe90356f4f85ac36ff9167 SHA-1: c5d5e81c3138cf78668a2834e72890e3b427078b SHA-256: 3bde3a1491d0c99282d066a2e0f42ed5b2aafae38b252e25435465adb18b66f6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains a link farm pointing to compromised WordPress uploads and other disposable hosting, suggesting an attempt to distribute malicious content or phish users. No scripts were extracted, but the PDF structure itself facilitates the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://zkojicin.cz/userfiles/file/vuranomikizoxo.pdf In PDF document text
    • http://malabarisproducoes.com/arquivos/files/73549686272.pdfIn PDF document text
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/3056b9b695d554b256e6d96826d99b83/22726377430.pdfIn PDF document text
    • http://anthonyjcincottalaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/vudoxonewodajuzusixupus.pdfIn PDF document text
    • https://hanoihome.net/img_duhoc/files/90609498836.pdfIn PDF document text
    • http://bizbecho.com/pa/trainstation/uploads/image/file/1673115121.pdfIn PDF document text
    • http://klubbelgickychobrov.sk/editor_uploads/files/7630963132.pdfIn PDF document text
    • http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607aa0230e8fc---zijuw.pdfIn PDF document text
    • http://osc-pribor.ru/products_pictures/file/sojokelofuv.pdfIn PDF document text
    • http://firstcuwire.com/file_media/file_image/file/ragekenowi.pdfIn PDF document text
    • https://avgdesign.com/userfiles/file/31710224567.pdfIn PDF document text
    • http://www.tekkoo.net/images/library/File/83471401090.pdfIn PDF document text
    • http://transinfosoft.com/userfiles/file/fusegikukixewo.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/16080b6dbbe01f---dozafizosudebi.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/8ef31222c1b7d81ad91275a66cfe2db4/sunexidales.pdfIn PDF document text
    • http://edwardnugent.com/userfiles/files/17484298745.pdfIn PDF document text
    • http://www.aadhar-interior.com/userfiles/file/dabujafefugezitil.pdfIn PDF document text
    • http://cocoal.com/uploads/file/96992418658.pdfIn PDF document text
    • http://yogo110.com/userfiles/file/15866252219.pdfIn PDF document text
    • http://www.suffaheducation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160744f8119fd2---romufasebigoluzalowasesa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=carnatic+music+theory+books+in+english+pdfPDF 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_off00012dd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DD1 21704 bytes
SHA-256: 2512556b2dc98f9e3bba29572057b8a594a5aeb520d7b2d24c4dbbac98542f94
font_01_sfnt_off000165d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x165D6 11544 bytes
SHA-256: 6c878dcb6963689f2e85bf4d4a751d0af5fbc463a9b6ffe8ba4d91ab42fdc8ae
font_02_sfnt_off000180aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x180AA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1