Malicious PDF — malware analysis report

Static analysis result for SHA-256 51541625f8c683c8…

MALICIOUS

PDF

115.0 KB Created: 2021-06-13 07:41:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-25
MD5: 2afd623535518b103a1c40c897f4bed0 SHA-1: 222a02496bbaa3a02b65aa4e4f1f532613d6fab5 SHA-256: 51541625f8c683c81064000a3542c5fc5d052e5afce42d59165de68fd1d783e0
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 0.9998

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 https://smidgel.ru/uplcv?utm_term=headway+beginner+workbook+pdf+free+download PDF link annotation
    • https://agilitynd.com/wp-content/plugins/super-forms/uploads/php/files/274018fa16ee446aa03f5dd79130bf62/newejirufefufati.pdfIn PDF document text
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160af73f627a1c---55054305988.pdfIn PDF document text
    • http://diversecityuk.com/userfiles/file/33713605575.pdfIn PDF document text
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1608b37da5a460---tarazu.pdfIn PDF document text
    • http://www.franklinwebdesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094590ceeffa---zinojufekuvexunivoberabi.pdfIn PDF document text
    • http://atut-biuro.com/uploaded/file/kuvok.pdfIn PDF document text
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16076f7355f6cb---26905338498.pdfIn PDF document text
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607a1659060ea---namebepenozexo.pdfIn PDF document text
    • https://www.idromeccanicasrl.com/idromeccanicasrl.com/wp-content/plugins/super-forms/uploads/php/files/7b7f14ba99cdd885b06be2eb00997646/binarutipotetunuvefix.pdfIn PDF document text
    • http://bestbuyfromindia.com/userfiles/file/dikedupukegujagaluk.pdfIn PDF document text
    • https://mujeresenmovimientoplus.com/userfiles/file/3853968179.pdfIn PDF document text
    • https://traveltokiev.com/wp-content/plugins/super-forms/uploads/php/files/qmceuliljpg4mcelooq60pa4l0/nagumefejep.pdfIn PDF document text
    • https://hotel-la-licorne.fr/userfiles/file/49591499872.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a2c593cbc22---91851506526.pdfIn PDF document text
    • https://www.heracles-hotel.eu/wp-content/plugins/super-forms/uploads/php/files/9kid2s88esrhulc01k33s2c8vk/buwijufaragejafenive.pdfIn PDF document text
    • http://teaandtiarasottawa.com/clients/e/e8/e8f54e69a7463df9fd0adff13cd8e90f/File/vezamameduwusemapiwuruvu.pdfIn PDF document text
    • http://etcad.net/np/upfile/file/10283645477.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00017df9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17DF9 5388 bytes
SHA-256: 9258fe2d991066aa747ad5db4a69e7f2f5173a059e25eb489c5f418749b2f546
font_01_sfnt_off00019076.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19076 14752 bytes
SHA-256: 2361d91d1e1470ca99d2695f065c149cb6684c9277c878911e083d99644ead08