Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f98cc1422679eb3…

MALICIOUS

PDF

87.4 KB Created: 2021-06-10 03:10:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 34cc82c8754f7eb188ab601c3261b36e SHA-1: 0a3b25d23e80c8000d91b97b2e32219bbb0e02bf SHA-256: 4f98cc1422679eb3ac52e890fe6de32e2c11d99e6face46abf136e6bba565ccc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links pointing to various domains, many of which appear to be compromised WordPress sites or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://medvor.ru/uplcv?utm_term=4th+grade+subject+and+predicate PDF link annotation
    • https://kimtuong.vn/isc/public/files/fckupload/file/feduluwijisimenamajobuxun.pdfIn PDF document text
    • http://computerdoki.hu/user/file/32922381159.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608141ed6b17c---29936014455.pdfIn PDF document text
    • http://theopenhouseclub.com/wp-content/plugins/super-forms/uploads/php/files/77ddac0fd632c544e65c4805a22d8b05/tuwamivezedimuramaxupo.pdfIn PDF document text
    • https://aihr-iadh.org/uploads/FCK_files/file/gomujuzegoralidul.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/93daaca46d476b73305e0131fc95854f/61934663108.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094ccaa4327e---kiwiragafokaremuk.pdfIn PDF document text
    • https://szabobuszrendeles.hu/files/files/zuwipoxizabijafi.pdfIn PDF document text
    • https://www.helpforbusymums.com/wp-content/plugins/super-forms/uploads/php/files/18f6fb46a8cd33dd56146df67025d63d/pelikepegofumotidulemabeg.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bb1e04efa6---pebizunipoforot.pdfIn PDF document text
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608aaacc44282---sisifofuxilekurelurogalij.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/c5e9ed4c201bd898710d36023ccce628/64004376118.pdfIn PDF document text
    • https://namdolove.com/FileData/ckfinder/files/20210530_7B8A269827D4D9A9.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d922f16338---2704647227.pdfIn PDF document text
    • https://bikinibody.be/wp-content/plugins/super-forms/uploads/php/files/08g1kbutlrnn3vpq0j6hc2lv9p/liremozazaxogudula.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/160952ef574e23---mizodedonasefexav.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_off00011743.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11743 5512 bytes
SHA-256: 9dc921cfe8c536181a4244ddb67911e57274cca479b23585b0bcd7e95fe6872f
font_01_sfnt_off00012a05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A05 11432 bytes
SHA-256: 7a4bb70c1edef29222e95c2777c2e5a944a376216fa39b5d3a1131d171357f74