Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a03488dbc338d57…

MALICIOUS

PDF

92.1 KB Created: 2021-07-05 12:25:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 7c3f0fdb726acb314c8e2d0f785b4a05 SHA-1: 9e5e7723dfb54526fb3d488b8808cb314fa33eb0 SHA-256: 8a03488dbc338d5792e485f65d717e3e916199f6af69c5a1916101759879b3b0
156 Risk Score

Malware Insights

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

The file is a PDF containing a link farm that directs users to multiple compromised websites, many of which host other PDF files. This pattern is indicative of a phishing or malware distribution campaign, where the initial PDF serves as a lure to lead victims to malicious content. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

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://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097c070bfba4---nijij.pdf In PDF document text
    • https://signika.pl/Upload/file/vugofewuw.pdfIn PDF document text
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/918f2230182b7e2710b16e64777e429e/27300443198.pdfIn PDF document text
    • https://chokysitohang.com/Uploads/userfiles/files/kosatodogofudoku.pdfIn PDF document text
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b4e75520ab---tadapeforiwosodawi.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16094bbfc7d8d8---wuvimuv.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16075c170eb5b9---tiwos.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/160ad2b41960c4---gajenokabogazofipepipig.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1609beed2b9b5c---76044130121.pdfIn PDF document text
    • https://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/d7555566c74f34f3947ab82f395f91a9/41005706502.pdfIn PDF document text
    • https://agatanorek.com/files/file/gepujusokoweb.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/7f5ef0337b24cca102f9a9bec72b3d17/49915419511.pdfIn PDF document text
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609422c1c301d---kukepagedemorasonudikuj.pdfIn PDF document text
    • http://www.euro-fly.eu/userfiles/files/93959158078.pdfIn PDF document text
    • https://tims.ro/ckfinder/userfiles/files/gemufekulekuvekosu.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16073bed04697c---busesumedebajukaj.pdfIn PDF document text
    • https://maturana.cl/upload/file/76550661999.pdfIn PDF document text
    • http://pettwayfamilyreunion.com/clients/39389/File/56505838481.pdfIn PDF document text
    • https://deedpoll.sg/wp-content/plugins/super-forms/uploads/php/files/ec53c5c698a37a6f6fee6928d0779e2d/patonivukarabinegar.pdfIn PDF document text
    • http://cgl.lu/userfiles/files/mojobuxexudepewu.pdfIn PDF document text
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/bgsvt1ejii5kvij8kr9v19hooh/42841535586.pdfIn PDF document text
    • http://inspirationallabels.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160bdc0f2e5a51---37164585263.pdfIn PDF document text
    • https://gelblighting.com/userfiles/files/1218303854.pdfIn PDF document text
    • http://x04ydivan.ru/userfiles/file/puwatijanogop.pdfIn PDF document text
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16078539a9f6fb---nunarefumazufive.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=the+mortification+of+sin+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_off000103d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103D4 10800 bytes
SHA-256: 5fd1fb401e3ba71105f7f57d40ea411eed6c226098e083ffc07678ccbb422dc0
font_01_sfnt_off00011c85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C85 17860 bytes
SHA-256: fc8ac8d529a1317fed6724cfc3b6bcafe225b9ee1621c0db225892e614d0c99a
font_02_sfnt_off00014b29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14B29 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1