Malicious PDF — malware analysis report

Static analysis result for SHA-256 c91a85bb2fbe2f77…

MALICIOUS

PDF

79.0 KB Created: 2021-09-06 10:10:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 9a352239dc40cdbd7340a18468e66d87 SHA-1: 8903374de8c464fd3a4c48a54223d0af487c0af5 SHA-256: c91a85bb2fbe2f77a6708e7833c9512944183de34da6870b4c44d15121789521
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 0.9949

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://intekcanada.com/ckfinder/userfiles/files/4366075274.pdf In PDF document text
    • http://bobiniauto.com/userfiles/file/87139651959.pdfIn PDF document text
    • https://graffitipaintstudio.com/wp-content/plugins/super-forms/uploads/php/files/dbc3ddbb0a152be2c0ad1388b822d0a2/vusukodasax.pdfIn PDF document text
    • http://hlqh.net/userfiles/file/20210823222826_1431526531.pdfIn PDF document text
    • http://frankslawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/70221061501.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611edb9b1bff2---45970444737.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/1116002488.pdfIn PDF document text
    • http://kangs78.com/clients/66216/File/ponurolefumudo.pdfIn PDF document text
    • http://quatanggiabao.com/images/uploads/files/54222606105.pdfIn PDF document text
    • http://gzcil.com/uploadfile/files/80313376921.pdfIn PDF document text
    • https://nevisnews.com/userfiles/tanatasedo.pdfIn PDF document text
    • https://infoenergie-loire.org/userfiles/file/bopolipazajosipiwerakisa.pdfIn PDF document text
    • https://www.retake.dk/ckfinder/userfiles/files/97621405759.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085653d8ac82---visafab.pdfIn PDF document text
    • http://maurovalleferroarchitetto.eu/userfiles/files/36944208534.pdfIn PDF document text
    • https://lsp.od.ua/wp-content/plugins/super-forms/uploads/php/files/119p38g2m8ml0003qltgjcmul7/55611676421.pdfIn PDF document text
    • https://avenue102.com/uploads/file/wekatawupune.pdfIn PDF document text
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0f24b871fa---kaxizelevelusodos.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/16092115378a19---64217336359.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/g9vjo5s9nuutblblaef2u1our5/xorutumutadedij.pdfIn PDF document text
    • http://aprendanow.com/wp-content/plugins/super-forms/uploads/php/files/91a4f4e75282510a3c421ca158c076b0/zexijonuvunogaraloxur.pdfIn PDF document text
    • http://hornets88.com/clients/56662/File/24419478298.pdfIn PDF document text
    • https://afd.me.uk/wp-content/plugins/super-forms/uploads/php/files/ohdaggpl5uv7eqgm2mapeh8991/lukonipaxofisujub.pdfIn PDF document text
    • http://klubalfa.org/img/userfiles/file/wewire.pdfIn PDF document text
    • http://sevoir.hu/uploads/file/mavusiboporetepumufigam.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=orthogonal+array+tables+pdfPDF 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_off0000d07d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD07D 17184 bytes
SHA-256: a8e9ae588948e02981455eff105476e47567c759fe81b58b4d70d40854388e5b
font_01_sfnt_off0000fd32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD32 10964 bytes
SHA-256: 9b6a5dc7b35e3241a31c905d0584083522c1970f93776420cb45ccaadab2cfcc
font_02_sfnt_off00011644.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11644 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1