Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a9773b225659e82…

MALICIOUS

PDF

98.7 KB Created: 2021-07-21 21:14:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 858005b3a59a9d189f6caa2cc183918f SHA-1: ec3279926a5ba8e71ea6e4ad6f7f4f4a0beaca93 SHA-256: 8a9773b225659e829c2fe6196bcece93308a116c7c463bf1be1b880ab34b46b4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to compromised CMS upload directories and disposable domains. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, lacking discernible user-facing content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 http://dieta-plus.pl/userfiles/file/2519911628.pdf In PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/3cead7e73d9624e73d2ec120d58b81b1/samagitawoze.pdfIn PDF document text
    • http://dongkoo.com/uploads/editor/files/tomizegudipeperelutosuj.pdfIn PDF document text
    • http://ghinelliarchitettura.it/userfiles/files/47141239100.pdfIn PDF document text
    • https://jgmurphy.com/wp-content/plugins/super-forms/uploads/php/files/69ae109285a70a05e5ce2910e784660b/25510869949.pdfIn PDF document text
    • https://emmaushuis.org/pages/simutejinorilokudi.pdfIn PDF document text
    • http://emmanuelmissionarybaptist.com/clients/74938/File/2635773282.pdfIn PDF document text
    • https://noihoithanhtuan.com/media/ftp/file/79909483388.pdfIn PDF document text
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/f9794d5b7624b07a062807a8a4b708b2/munog.pdfIn PDF document text
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9f70208eb6---83561753289.pdfIn PDF document text
    • https://bilbox.es/wp-content/plugins/super-forms/uploads/php/files/cc67b2c89e178165dfed5734d63b69a7/tuluvovem.pdfIn PDF document text
    • http://in-dapt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f5539c7434---ximezibigoze.pdfIn PDF document text
    • http://global-insurance-broker.de/downloads/61619512113.pdfIn PDF document text
    • http://chokmanee.com/userfiles/file/21617646688.pdfIn PDF document text
    • https://www.aironface.com/wp-content/plugins/super-forms/uploads/php/files/88f6b91ae3815611f5f823a112fd4bcb/97044197595.pdfIn PDF document text
    • http://pijntherapie.be/uploads/files/39146973413.pdfIn PDF document text
    • http://cheumst.com/upload/fckeditor/file/31660902001.pdfIn PDF document text
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/160b213b677233---diwitapavanuxij.pdfIn PDF document text
    • http://enricobarraco.com/files/60106396251.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/8803bce834783a01dfbbd142b313b132/35410510223.pdfIn PDF document text
    • https://aartipalette.com/userfiles/file/22139114392.pdfIn PDF document text
    • https://www.demetagras.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fabbfe02bb---tutiperud.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160e6ab8cce900---govagobobebajolug.pdfIn PDF document text
    • http://yngc.ru/admin/ckfinder/userfiles/files/rotipedafageke.pdfIn PDF document text
    • https://detector-billetes.com/Imagenes/file/33962513955.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=what+and+which+grammar+rulesPDF 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_off00011eda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EDA 10876 bytes
SHA-256: ef681b46991873ebf4fcbb6454399eae29770f5f75be5d9a540754ca3e801ea5
font_01_sfnt_off000137a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137A0 17068 bytes
SHA-256: 881cecc885c6138f4af3a7cb7861a7889f900ce9dae1917d91c3d966cb19ddca
font_02_sfnt_off0001641c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1641C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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