Malicious PDF — malware analysis report

Static analysis result for SHA-256 85c65c79a1dbd38d…

MALICIOUS

PDF

134.8 KB Created: 2021-07-30 15:24:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a0bbcf68f65ab0aed5a6c08a11cc7317 SHA-1: 04dd8384d58906b3647c2f65d0ae4ed110d051ba SHA-256: 85c65c79a1dbd38d4af9bcd6bf07e093e46b45c1ed7b4c6070c17fee7b17b9c0
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for delivering malicious content. Heuristics indicate the PDF acts as a link farm, pointing to multiple compromised websites and disposable hosting, likely to distribute malware or conduct phishing. The ML classifier and ClamAV detection strongly suggest malicious intent, with the embedded JavaScript likely responsible for redirecting users to these external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609089912771b---8766995245.pdf In PDF document text
    • http://parejalecaros.com/adjunto/upload/fck/files/jiwuwejufazuwop.pdfIn PDF document text
    • https://hanakspotrebice.cz/eshop/ckfinder/userfiles/files/39737169999.pdfIn PDF document text
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/160910ce5c5d0f---dalarugixuguzukorizuxim.pdfIn PDF document text
    • https://www.keystonecare.co.uk/wp-content/plugins/super-forms/uploads/php/files/ace0227be78046e4620a34caeab6c298/nutuk.pdfIn PDF document text
    • http://lexus-custom.com/js/upload/files/25882732031.pdfIn PDF document text
    • http://mea-travel.pl/userfiles/file/sodazuw.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/988d0a099c2a1efa2adbfde170a38450/jimalixojebikukubuxixetav.pdfIn PDF document text
    • https://jordanadams.com/ckfinder/userfiles/files/90045072443.pdfIn PDF document text
    • http://diamantina-joaillerie.com/ckfinder/userfiles/files/tuvupadixezotaru.pdfIn PDF document text
    • https://joinvita.com/neu/userfiles/file/rorodizumimuzonumirofup.pdfIn PDF document text
    • https://n95america.com/wp-content/plugins/super-forms/uploads/php/files/2d660077bb6620b2a2d55b418869517a/baxezunumu.pdfIn PDF document text
    • http://sakaryakasaplarodasi.org/userfiles/file/21658996066.pdfIn PDF document text
    • http://sistersaviopublicschool.com/userfiles/file/wesezapulujirosa.pdfIn PDF document text
    • https://sf-tfi-pgu.uz/wp-content/plugins/super-forms/uploads/php/files/00ed9fbf88faaa5d63e45cc8ce86a543/xaterapexanaje.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607f457e2687e---48091362869.pdfIn PDF document text
    • http://marmaraisg.com/images_upload/files/85146005564.pdfIn PDF document text
    • https://weekendtripskolkata.com/userfiles/file/15587237917.pdfIn PDF document text
    • http://chiengthai.com/file_media/file_image/file/47892061446.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/160acffe34acd0---8540501440.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=figuras+retoricas+ejercicios+interactivosPDF 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_off0001ac8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1AC8B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001c49d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C49D 18416 bytes
SHA-256: d25b064f8e7822592d1d454090b8a6455e30e726da79ab1291e69aa3409142ea
font_02_sfnt_off0001f2d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1F2D3 10632 bytes
SHA-256: 0c491d407b2f6f157394dd7fe13a8501a189e0c56dde5dfe74102d75f2444372

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