Malicious PDF — malware analysis report

Static analysis result for SHA-256 c85308853eb1e613…

MALICIOUS

PDF

97.2 KB Created: 2021-07-31 18:58:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: 06f1827576028572d2431dd8eac999af SHA-1: 1eabc9541ee6f36204e52359c0693cb977fee833 SHA-256: c85308853eb1e6131135f9eb80811b224d862e559aee34f345bf73c946ffd6b7
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

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 and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://seashoresilverlabradors.com/clients/4/48/482fd9669fb3260065120a60ccac5e48/File/71556201227.pdf In PDF document text
    • http://teerosy.com/ipp/images/uploads/files/gotizubumazel.pdfIn PDF document text
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c000ee1ab00---tosukugibubixasapimav.pdfIn PDF document text
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/blm3fjbkbidhtapokis7n1uhja/24810666699.pdfIn PDF document text
    • https://3dreamvr.com/wp-content/plugins/super-forms/uploads/php/files/1715e382d5e50c1c70175e3641c68f1e/narezijubelog.pdfIn PDF document text
    • http://mosvag.ru/img/lib/file/54484680596.pdfIn PDF document text
    • http://gsmontaggi.it/userfiles/files/75028465779.pdfIn PDF document text
    • http://webscape.co.bw/wp-content/plugins/formcraft/file-upload/server/content/files/160b83e4ce3b95---70054740898.pdfIn PDF document text
    • https://chmelo.hu/sites/default/files/file/76471369733.pdfIn PDF document text
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c5b6c2e24ee---kafonetovunuwanugere.pdfIn PDF document text
    • http://sibmetiz.ru/upload_picture/kemiputijajelibowur.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f3952e816b---13900208972.pdfIn PDF document text
    • http://kapli74.ru/upload_picture/lajawabilipero.pdfIn PDF document text
    • http://vipavtoufa.ru/wp-content/plugins/super-forms/uploads/php/files/0b686bd48029670d349483861e38b17b/20514398494.pdfIn PDF document text
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16093f993aad6c---28655130791.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a37e4755e4d---jumujomo.pdfIn PDF document text
    • http://www.aportecnica.com/imagenes/editor/file/37900155184.pdfIn PDF document text
    • http://aylincinarli.com/fckfiles/file/85706777855.pdfIn PDF document text
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/a1179fdf65c977d86504800aeee0a00b/vaditatu.pdfIn PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160aac20a303a5---72182473413.pdfIn PDF document text
    • http://wellfoto.cz/pictures/files/bumevinabemajopijirujor.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160ae9fe493fe8---ginowo.pdfIn PDF document text
    • https://lightsourceindiana.com/wp-content/plugins/super-forms/uploads/php/files/c778fed6029fe9a48b08c90b5c40cbbb/95667700313.pdfIn PDF document text
    • http://bio86.fr/fichiers/bowajixoregitiwa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=employee+monthly+attendance+sheet+format+in+excel+free+downloadPDF 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_off000115cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012de4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DE4 11168 bytes
SHA-256: 68d57feb1413182c92b82339be701b8bafc1c5eabd079b6d39b3814e0a3204ff
font_02_sfnt_off000147d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x147D2 17452 bytes
SHA-256: 83b28ceb7ab360571c687988d958a142a81ee4169b2cc194dfa9a4b68bf3eade