Malicious PDF — malware analysis report

Static analysis result for SHA-256 a900d52987ebd6f0…

MALICIOUS

PDF

96.9 KB Created: 2021-09-02 16:06:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: cafc7f80b4cc254316959fb9c248eba7 SHA-1: 71606f06ead445ca8530dde11fef6c49ea78f17a SHA-256: a900d52987ebd6f0cd7e0302d67784e88888a2e0472a87d74ccd764c8cfa7736
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The file contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting a phishing or link farm attack. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, lacking clear user-facing content but containing embedded artifacts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://huntic.ru/uplcv?utm_term=blaupunkt+bluetooth+speaker+user+manual PDF link annotation
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607afbbaa47f4---siditajejibunowegowozo.pdfIn PDF document text
    • https://divinesacredshakti.com/wp-content/plugins/super-forms/uploads/php/files/e99ec29a15967be840ac0e3758613b42/dogena.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cbda23c9aa7---68480883500.pdfIn PDF document text
    • http://pappteam.hu/userfiles/file/17292324994.pdfIn PDF document text
    • http://skogsformedling.se/bilder_umeny/File/65877063581.pdfIn PDF document text
    • http://citescolairedeledit.com/include/file/wuvusowovatowasev.pdfIn PDF document text
    • http://geose.ru/userfiles/file/16723680330.pdfIn PDF document text
    • http://chipublichouse.com/ckfinder/userfiles/files/sapegupakojemoxiv.pdfIn PDF document text
    • http://svenstavik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ddb4563ec6---topijeliduloxasaluz.pdfIn PDF document text
    • https://amitadevnani.com/userfiles/file/soropudufakolepetafejizi.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e6b0ed58070---53158083335.pdfIn PDF document text
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/7e273f77df721ca9a6d06bc8a09e8924/80739014021.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/16080a1bf22c55---bugavo.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/vja1od8fhq9l13qs44hmhc7o11/pewok.pdfIn PDF document text
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a60c437c584---boloxobamuxatapajop.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1607022edbba30---92783535490.pdfIn PDF document text
    • https://aashianarealty.com/file/44535222673.pdfIn PDF document text
    • 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_off00010e5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E5A 10808 bytes
SHA-256: 0fced1c396788dd78ff2090fe0021278d757e2e0de170b450097cbb0114baa8e
font_01_sfnt_off000126eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126EB 21368 bytes
SHA-256: d9228731df18e4b59511929778dfe8475912193b92d6ba9f463408160d25a7a8
font_02_sfnt_off00015e71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15E71 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1