Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c36648801d86fe2…

MALICIOUS

PDF

89.3 KB Created: 2021-09-06 19:50:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 935704ac2a38afca8ff9774fb3d242aa SHA-1: 4b4feece9b1305aa63d0c50602e939c1bc375c48 SHA-256: 5c36648801d86fe25606926098e060c413c89f355b9388d0cb9a5e0cefaf0bb4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS upload directories or are part of a link farm on disposable hosting. The primary attack pattern involves luring users to click these links, likely leading to further malicious content or phishing attempts. No scripts were extracted, but the PDF structure and embedded URLs strongly suggest a phishing or malware distribution vector.

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 https://www.mixedclass.com.au/wp-content/plugins/super-forms/uploads/php/files/liu0sea4vrv4knpnn4b0es3ch0/vejowixufux.pdf In PDF document text
    • http://floridare.ru/app/webroot/img/uploads/file/241801_reregikiruka.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/14511e036b529b4b62cf891544cfda4e/2354714843.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e159c5a3eb5---73111038838.pdfIn PDF document text
    • http://bennett-legal.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/sabosodixo.pdfIn PDF document text
    • https://yziact.fr/wp-content/plugins/super-forms/uploads/php/files/khpa39emf0lhfs32a68qoe48nk/83524933539.pdfIn PDF document text
    • https://esz.jp/img/editor/files/numopikaparopazakonokeba.pdfIn PDF document text
    • http://ned.ru/uploads/files/92980514574.pdfIn PDF document text
    • https://farmacieitaliane.com/documenti/file/80838548288.pdfIn PDF document text
    • http://limeitec.com/upfiles/editor/files/63130533850.pdfIn PDF document text
    • http://ptk-astana.kz/wp-content/plugins/super-forms/uploads/php/files/c317aaacc0a50a648e637e84ed285714/21174176448.pdfIn PDF document text
    • http://farmaciafici.com/userfiles/files/tawapawi.pdfIn PDF document text
    • https://mytutr.com/wp-content/plugins/super-forms/uploads/php/files/f18b625a86d112b35ae3da0bf6a19dab/76575799517.pdfIn PDF document text
    • https://purevdavaa.mn/uploads/ckfinder/files/nerubosuxoraxexokewok.pdfIn PDF document text
    • http://auto-spec.ca/fck/file/85223603319.pdfIn PDF document text
    • https://gangwontaxi.com/FileData/ckfinder/files/20210720_0788F87A15C6C2E9.pdfIn PDF document text
    • https://lajovisena.com/gallery/file/52200740409.pdfIn PDF document text
    • http://bakoca.hu/files/file/92279443459.pdfIn PDF document text
    • http://ranaghatpchsschool.org/userfiles/file/vesivazinafa.pdfIn PDF document text
    • http://eg-connect.com/php_codes/Scott/VieauAssociates/code/userfiles/file/58229077340.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=comunidad+primitiva+en+el+peru+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_off0000f1b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1B2 20868 bytes
SHA-256: 534500acf0d20ea23648274959ae2d6f35494ac237d8b08bc18fc1bd3bb5ba81
font_01_sfnt_off0001277b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1277B 10688 bytes
SHA-256: 69cabd0a9f647ee9094515bfba726b07a504735111cac515bd3c8d30f818de86
font_02_sfnt_off00013ffa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13FFA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1