Malicious PDF — malware analysis report

Static analysis result for SHA-256 81275acf91134309…

MALICIOUS

PDF

69.8 KB Created: 2021-09-29 01:16:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 1cb9a367afa9683f287e916e7e794a32 SHA-1: 2da1152d5a0fa6a7ab17bc423dc6611d2b1f9808 SHA-256: 81275acf91134309d1dffaab02159456cc82d3e8eae7d10a5d3167cca052793b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by a machine learning classifier and ClamAV. It contains embedded JavaScript and numerous links pointing to compromised websites, indicating a likely phishing or malware distribution scheme. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the PDF is part of a link farm on disposable hosting, further supporting its malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://contabilidadegoncalves.com/fotosempresa/files/21797746758.pdf In PDF document text
    • http://www.szphotar.com/admin/img/files/43864874498.pdfIn PDF document text
    • http://raegcafe.com/uploads/files/narufavezatusimaro.pdfIn PDF document text
    • http://pantanalmsnews.com.br/ckfinder/userfiles/files/34609206124.pdfIn PDF document text
    • http://reklama-kemerovo.ru/files/files/7081844311.pdfIn PDF document text
    • http://355353.ru/userfiles/file/gunaremosakemewig.pdfIn PDF document text
    • https://kingwaterpure.com/ckfinder/userfiles/files/zagaki.pdfIn PDF document text
    • https://clove7.com/userfiles/file/77555068043.pdfIn PDF document text
    • http://otczenacts.com/media/files/zakotajomujawufanupefu.pdfIn PDF document text
    • https://reclamesticker.nl/images/uploads/file/In PDF document text
    • http://cainghienbinhduong.com/uploads/userfiles/file/mizabasozazametevusifeza.pdfIn PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614026e6bb215---fonesivita.pdfIn PDF document text
    • https://atarentacarburdur.com/userfiles/file/6292803522.pdfIn PDF document text
    • https://nanyangtextile.com/userfiles/file/12897823752.pdfIn PDF document text
    • http://www2.grupoksl.com.br/js/ckfinder/userfiles/files/29027604592.pdfIn PDF document text
    • http://linpus.com/app/webroot/userfiles/files/33211345906.pdfIn PDF document text
    • http://quiltingacademy.net/fckeditor/userfiles/file/56687085034.pdfIn PDF document text
    • http://mlight.cz/archiv/file/gefidapo.pdfIn PDF document text
    • https://proxkimya.com/resimler/files/48640823398.pdfIn PDF document text
    • https://christianboudreau.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141f20ab7092---47222718575.pdfIn PDF document text
    • http://furniture83.com/upload/files/bugipisoboborozabujidufi.pdfIn PDF document text
    • https://majubesar.net/contents/files/kumoxufagebilebojob.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1614dce201d1a7---3146769493.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=the+hunger+games+2+summaryPDF 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_off0000aff4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFF4 10496 bytes
SHA-256: 5854d03f2ab0be789d5af121310f5ca263903de06cea04c52105e5e39c67902f
font_01_sfnt_off0000c7af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7AF 16504 bytes
SHA-256: 255e3b843732d8b97e8e28ba08908e6eec666ebffdd6f252f978c5415c90a49d
font_02_sfnt_off0000f1d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1D7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1