Malicious PDF — malware analysis report

Static analysis result for SHA-256 25765798cea604f3…

MALICIOUS

PDF

84.4 KB Created: 2021-08-24 21:35:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-17
MD5: ca44b7acdcebe68cbf01ff381cb98c30 SHA-1: 31f82f031cdcfda4ef9fea3c1350809ac7ea7869 SHA-256: 25765798cea604f38dbbbb0f356b18e5d6101126cacc02f02cd22d9345fc8906
156 Risk Score

Malware Insights

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

The PDF file contains numerous links pointing to compromised WordPress sites, indicating it functions as a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution through these links. The document body is heavily obfuscated and unreadable, providing no direct content clues, but the heuristic firings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9924

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://realestateconnect.biz/wp-content/plugins/super-forms/uploads/php/files/h6pote1qtrc4a2avd3rc7phbp0/98972022453.pdf In PDF document text
    • http://inewbus.com/wp-content/plugins/super-forms/uploads/php/files/luemv8hjpepsl498eqn0m6ljm5/pobuposape.pdfIn PDF document text
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/6ru6j6lcnp54djkaefiqsh05c7/3269940727.pdfIn PDF document text
    • http://agataklimowska.pl/userfiles/file/44435686959.pdfIn PDF document text
    • https://sipsib.ru/wp-content/plugins/super-forms/uploads/php/files/1531602729eee4565e57b5d07011b8ce/20527275711.pdfIn PDF document text
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/60688d7fca6a1bccf7fc4c23ecc4a47f/xobamo.pdfIn PDF document text
    • http://afghansolar.com/userfiles/file/demegugun.pdfIn PDF document text
    • http://cuspsurgeons.com/userfiles/file/pifesupimiwowenokir.pdfIn PDF document text
    • https://xn----8sbcehyodmtf1czh.xn--p1ai/userfiles/file/30482479210.pdfIn PDF document text
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082aa19e2b83---82888373799.pdfIn PDF document text
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/i1v4cr2s5m7agnr9qr55lchcns/fapimejepefin.pdfIn PDF document text
    • http://svx.su/ffile/file/jiruvojogefemumojulu.pdfIn PDF document text
    • https://kurtwohndesign.ch/userfiles/files/80249740673.pdfIn PDF document text
    • https://kp-bs.ru/upload/files/83929541822.pdfIn PDF document text
    • http://mevlanaasm.com/resimler/files/tuzogurevumepe.pdfIn PDF document text
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a4404e65d6---49125229612.pdfIn PDF document text
    • http://worldofpacifiers.com/editor_uploads/system/files/31964815342.pdfIn PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1609428a6aab92---gagaxenatej.pdfIn PDF document text
    • http://keyflounge.nl/userfiles/file/10162372604.pdfIn PDF document text
    • https://spaslask.pl/wp-content/plugins/super-forms/uploads/php/files/20qio2sp5qf3raej5bql36tajd/tegoj.pdfIn PDF document text
    • http://ledins.lv/cms/file/69519027934.pdfIn PDF document text
    • https://tecnomatec.cl/upload/file/jetekugipuniwa.pdfIn PDF document text
    • http://jatechkj.pl/upload/fck/file/46477293749.pdfIn PDF document text
    • https://laihouston.com/wp-content/plugins/super-forms/uploads/php/files/00a168525ab39940fb9c5977312789f8/46655106005.pdfIn PDF document text
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/15330da3bd91a41f562eab90406f7691/52357951280.pdfIn PDF document text
    • http://comicpapyrus.com/wp-content/plugins/super-forms/uploads/php/files/a3d2c8dabb7d24b87546890c09443b52/15696839686.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=one+sample+t+test+apa+formatPDF 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_off0000e84c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE84C 10452 bytes
SHA-256: 2ad194efbabe5ba48a1b7201255ae3462241e35b55ba61df10c7c3a4cdac6b03
font_01_sfnt_off00010014.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10014 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011826.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11826 16528 bytes
SHA-256: 6bb4671208e0afe8190ef97401a35442ff6f3a32979595c1ec75fae84e162d0b