Malicious PDF — malware analysis report

Static analysis result for SHA-256 91de7e176fb37c94…

MALICIOUS

PDF

88.7 KB Created: 2021-08-08 15:09:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-01
MD5: 7e7cebf07e9853260cfd069136f3cf63 SHA-1: 80807b5e93f6c9cd9e5ae4ee87497c6a0c55f1f9 SHA-256: 91de7e176fb37c944a0c78a667cb40bab4970a8bd109b41f1cfe87965f467dbf
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://irlanc.ru/uplcv?utm_term=station+eleven+book+pdf+download PDF link annotation
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8619d2e6e---karamarewasufovu.pdfIn PDF document text
    • https://www.mii.net/wp-content/plugins/super-forms/uploads/php/files/4d248722de0d00d7fee9dd25a686f382/27697776449.pdfIn PDF document text
    • http://agataklimowska.pl/userfiles/file/14378976256.pdfIn PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/16092472adbf9e---xoxowufosifirukek.pdfIn PDF document text
    • https://relans-nn.ru/images/docs/file/4843224803.pdfIn PDF document text
    • https://www.paparazzirestaurant.com.au/wp-content/plugins/super-forms/uploads/php/files/c3b6bd3f0d26e5281237b058ee843215/pivijinebima.pdfIn PDF document text
    • https://skyfireconsulting.com/wp-content/plugins/super-forms/uploads/php/files/l9ngpd14fsvjhc2alt7rrb8a8h/xibobitorije.pdfIn PDF document text
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/glrfcbotdhb3en3akvfj0fm1nt/50278898083.pdfIn PDF document text
    • https://posh.hr/files/jafuvupunedilozegas.pdfIn PDF document text
    • https://clubslotalmatriche.com/calcas/file/25071302548.pdfIn PDF document text
    • https://jcmimoveis.com/userfiles/file/91321846192.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/160908952e801c---27925091662.pdfIn PDF document text
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1607402e89e7c3---futukafogovadibus.pdfIn PDF document text
    • http://immopolignano.lu/images/muzoxafuromuzupaz.pdfIn PDF document text
    • https://interesttour.com/wp-content/plugins/super-forms/uploads/php/files/e9718c8742d60c308d0db119244db648/34678294769.pdfIn PDF document text
    • http://qdjshg.com/files/file/3469819.pdfIn PDF document text
    • https://avantkart.com/wp-content/plugins/super-forms/uploads/php/files/6ln18cru3dicbpeemk1d1k12u3/gipegufamonux.pdfIn PDF document text
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d00b3581c43---dodegetefasawozu.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c2c0aa89ba9---nukifesaxamonuwuzajasa.pdfIn PDF document text
    • http://toyotarent.tw/FileData/ckfinder/files/20210713_6A40E4F2255A6D03.pdfIn PDF document text
    • http://geology.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160b05f5d6e857---91620418703.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16070052841ca9---52703731171.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_off0000f83b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF83B 10680 bytes
SHA-256: a90dc70c431497087ed245a033f503f7ee418f9c047de4169ebf7f93eefe9ab9
font_01_sfnt_off000110a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110A9 16844 bytes
SHA-256: 71e34f9656e801d1401419e61f7f04777b1dec81e65b80d27200561c372e4060
font_02_sfnt_off00013cbd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13CBD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1