Malicious PDF — malware analysis report

Static analysis result for SHA-256 f9d6e1b9df28e821…

MALICIOUS

PDF

72.3 KB Created: 2021-06-22 09:58:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: 7e24f69e89506fe5f33f598d83647ef1 SHA-1: 1f56800fac08556af5f592fa8138c654d2b4e8be SHA-256: f9d6e1b9df28e82130cc829b30fd8ec856731aaad9e0afe643a47dca8d76ffef
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains numerous links, many pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or malware distribution scheme. The document body, though heavily obfuscated, contains metadata indicating it was generated by wkhtmltopdf and mentions 'English worksheet for kindergarten', likely a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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.
  • 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.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/f48ee1e6a6bdc364e1ff32ce9bd8450d/36663832343.pdf In PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609464050aca4---xagamenigukolusojed.pdfIn PDF document text
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/160ba1560b4f74---kilavomizogetatabujin.pdfIn PDF document text
    • https://censcakmu.org/board/file/files/65876030250.pdfIn PDF document text
    • https://liniagdanskzydowo.pl/files/23275729067.pdfIn PDF document text
    • http://healthywithhart.com/res/file/rubakutupalisafunuse.pdfIn PDF document text
    • https://www.peeryhotel.com/wp-content/plugins/super-forms/uploads/php/files/151778ce293b3545deaff850fc960202/gokajizepesoni.pdfIn PDF document text
    • https://www.pharmaright.ca/wp-content/plugins/super-forms/uploads/php/files/f2isq3hlkcsg8ukve9vm0rsknu/26671169429.pdfIn PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/160897ca559c74---96495282471.pdfIn PDF document text
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7f09cefb6---44114116388.pdfIn PDF document text
    • http://onlinepravenconsultant.com/uploads/wysiwyg/files/rijovunosoxilon.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160beb0ae35ffd---63255210004.pdfIn PDF document text
    • http://sibleyestateplanning.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/59588710392.pdfIn PDF document text
    • http://status-go.net/gfx/userfiles/files/28808924991.pdfIn PDF document text
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606eab1164817---labato.pdfIn PDF document text
    • http://www.alexgis.com/siteuploads/editorimg/file/14351975765.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=english+worksheet+for+kindergartenPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000de3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE3F 5284 bytes
SHA-256: 943417a45cd955b3b341e85ddbe8220a2000cb09f8a5a5856449acffff1c47ed
font_01_sfnt_off0000f049.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF049 10628 bytes
SHA-256: b3e083bcce75fbae9104d1cd7dc5a941ec6227d4595417726b03be82547ccdf9