Malicious PDF — malware analysis report

Static analysis result for SHA-256 21b16973a4ec42bc…

MALICIOUS

PDF

87.6 KB Created: 2021-08-19 22:03:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 2ef5d8313079d3561243458611d5ee70 SHA-1: 21d4f4f154b0fc01cf9011781820df6d2274eba4 SHA-256: 21b16973a4ec42bc9029acd9f3ca19de9571668c23078b58b9d0be0c90e2609d
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://ustunongel.com/image/files/xitaxikuginadanegewujo.pdf In PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1607027d209e78---zutano.pdfIn PDF document text
    • http://xn--h1aeekk.xn--p1ai/files/file/78308212566.pdfIn PDF document text
    • http://tktravel.shop/FileData/ckfinder/files/20210714_F92B3967167E3834.pdfIn PDF document text
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/2jhm1ge15pn7ehnisr43u444li/xosafuribozito.pdfIn PDF document text
    • https://semut73.com/contents//files/jorigaju.pdfIn PDF document text
    • https://betenenergy.com/sites/default/files/file/nananadipak.pdfIn PDF document text
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/160c6b530641f1---tozegememujagubax.pdfIn PDF document text
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/2c84f41e28f911cd093d22c11bd2f0dd/39509900997.pdfIn PDF document text
    • http://spencerrandlefamily.com/clients/864257/File/43559811628.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608291d56f1cc---20991204533.pdfIn PDF document text
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16098cf14f07d5---24914367561.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160b7ce27714ea---53206093831.pdfIn PDF document text
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b0a3ae9a7b---duwidupofutamat.pdfIn PDF document text
    • http://senn60reunion.com/clients/876260/File/93952361246.pdfIn PDF document text
    • https://benchmarktransitions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a412738536a---69273232051.pdfIn PDF document text
    • http://namhungholdings.com/uploads/ckfinder/files/57671388342.pdfIn PDF document text
    • http://bigxra.com/uploadfile/file/2021070407424673499.pdfIn PDF document text
    • http://pronobile.de/catalog/file/52219193614.pdfIn PDF document text
    • http://beytarimcilik.com/admin/editor_resim/file/19558884915.pdfIn PDF document text
    • https://eandjfamilyhealthcenter.com/wp-content/plugins/super-forms/uploads/php/files/87992ad5e0dc70e95e166e0cd7fca9e6/bitelixazikojuzuxadelisar.pdfIn PDF document text
    • http://duonglaohanoi.com/userfiles/file/27019582174.pdfIn PDF document text
    • http://businessplan-capalpha.eu/mbp/upload/images/images/upload/ckfinder/49831581234.pdfIn PDF document text
    • https://jetzterstrecht.hamburg/wp-content/plugins/super-forms/uploads/php/files/9ocr1tp33rhubd254mt8e4bmv5/motisesesezorasakulujubo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=ecommerce+website+development+project+plan+templatePDF 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_off0000f39f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF39F 11080 bytes
SHA-256: 8cbf1111da7ec1dfbbe4a45f807b35e9bfe413a7ba8ce15e48f077fe6b7bde2c
font_01_sfnt_off00010d37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D37 16580 bytes
SHA-256: 3a371176c03f2bf23616c13ab63e2de10668f59371e6301cf398f308aa17ab32
font_02_sfnt_off0001385f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1385F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1