Malicious PDF — malware analysis report

Static analysis result for SHA-256 583ac378d5a81eb8…

MALICIOUS

PDF

85.9 KB Created: 2021-09-05 04:45:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: aef6387dac763cf71691c7b0cb404902 SHA-1: b3d98fcf85f7859e7736dc81e38ac9095eebf888 SHA-256: 583ac378d5a81eb82b55b8bee26849a6879d0d52ac86793d8c2ae7d7c0f68b69
156 Risk Score

Malware Insights

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

The file is a PDF identified as malicious by ML classifiers and ClamAV. It contains a large number of external links, many of which point to URLs hosted on compromised WordPress sites or disposable hosting, suggesting a link farm or SEO manipulation tactic. The presence of these links and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic indicate a likely attempt to direct users to malicious or manipulated content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 https://frigosztufi.ro/ckfinder/userfiles/files/nurowamugum.pdf In PDF document text
    • http://remont-elektro.eu/archiv/file/giwepiza.pdfIn PDF document text
    • http://stonestudio.pl/files/upload/file/78507143005.pdfIn PDF document text
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b9b38ee19b4---9023759331.pdfIn PDF document text
    • https://producto.works/userfiles/file/lorevudepexe.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16070475b88351---84408835293.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/b6a908e1bee33c4c072600205f7aea17/38591186937.pdfIn PDF document text
    • http://stlnsk.ru/uploads/file/gulefazegupobobakubelaf.pdfIn PDF document text
    • http://vinhthuan.com/upload/files/82065145024.pdfIn PDF document text
    • http://spbi.cz/res/file/rigukubetepepidapuw.pdfIn PDF document text
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/a84eed6f7c4af32ee8ec5da71653e971/kimawukenumoloriraki.pdfIn PDF document text
    • http://deborahmayerlawoffices.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/gujakonesomirakewawusik.pdfIn PDF document text
    • https://wills.sg/wp-content/plugins/super-forms/uploads/php/files/ca637718da35b1750ea42121a33e4031/zumazepijuginilur.pdfIn PDF document text
    • http://bjallstar.com/upload/file/52387032512.pdfIn PDF document text
    • http://asea-admin.com/_userfiles/file/20210502092020.pdfIn PDF document text
    • https://www.icicle-mountaineering.ltd.uk/ckfinder/userfiles/files/jurazumabofesunadowotaku.pdfIn PDF document text
    • http://bioident.pl/photos_fck/file/gobugusizubimifabuluta.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/lksivrana0pkef9qv0plv1e3b3/5059331167.pdfIn PDF document text
    • http://khautrangkhangviet.com/upload/img/files/36957710369.pdfIn PDF document text
    • http://bjjiffy.com/upload/deratij.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/16096057a568fb---71719724032.pdfIn PDF document text
    • https://najlepsze-w-polsce.pl/uploads/fikemalixoruzijapekusur.pdfIn PDF document text
    • http://sushikyototogo.com/uploads/files/58486882166.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=saadat+hasan+manto+books+pdf+englishPDF 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_off0000ebb4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBB4 17468 bytes
SHA-256: 44469fdb7d0ecae994eaa6e9babefae06f9b3f10ec6b965632689c04a3a47b8a
font_01_sfnt_off0001185d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1185D 11152 bytes
SHA-256: c3de6f7bdc40ab353601a0af1593acf729a46796e8e454f38a57f0a2afea8b29
font_02_sfnt_off000131c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131C0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1