Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d50cb2cd88d0403…

MALICIOUS

PDF

66.4 KB Created: 2021-06-18 17:32:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 32d49f962a3076ab23314f8386d245ca SHA-1: 28527def7357b719bf22bb3b8540f489012b6980 SHA-256: 8d50cb2cd88d040307328489b04fb87ccae6c849325fa88835372e322db789c0
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to compromised WordPress sites and other disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create PDF documents from web content, further supporting the lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://bakwanudang.com/contents//files/juxititunitotofot.pdf In PDF document text
    • http://atdawnwelift.com/userfiles/file/kapidapeziposilekuwer.pdfIn PDF document text
    • https://svetpoznaniyaonline.ru/wp-content/plugins/super-forms/uploads/php/files/14414e8f6aece095053b98c313ef1ebe/solilazud.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/c979ffadce778d0ab67d7cb73634ea6f/walufibojapanapofofu.pdfIn PDF document text
    • https://biogenetixpharma.com/ci/userfiles/files/58264722917.pdfIn PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099fb45494b9---55076411893.pdfIn PDF document text
    • http://avision-italia.com/userfiles/files/revitatakelog.pdfIn PDF document text
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095dfbc6d411---wagilanudibimusukizefi.pdfIn PDF document text
    • https://notofthisgalaxy.com/wp-content/plugins/super-forms/uploads/php/files/qcdtm4o2qdavqtrcbaompmnc1k/1495720657.pdfIn PDF document text
    • https://gradeagroup.com/wp-content/plugins/super-forms/uploads/php/files/334l6corgc65d538e6ttt2g25f/japuzazanefewitolizoke.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608e32583927f---32356998929.pdfIn PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c110b2bf5ec---23165008106.pdfIn PDF document text
    • http://www.platformliften.info/wp-content/plugins/formcraft/file-upload/server/content/files/160c5aeeac4536---72736739518.pdfIn PDF document text
    • https://fobiy.net/wp-content/plugins/super-forms/uploads/php/files/778489606a13d362612e435eecc119a4/nasaxubamafat.pdfIn PDF document text
    • https://space1500.com/wp-content/plugins/super-forms/uploads/php/files/997ed9cbe79c9f8f8e1f7243e1b8f266/mabepiz.pdfIn PDF document text
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/1741adfcb4f8da00d3c9e69bc5478953/ranaga.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/8a64359c38502008454272caee277986/8510880606.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=ss1+chemistry+textbookPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c38e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC38E 5328 bytes
SHA-256: 3c574f20854a64c473c0c94d46a2a19d3a8502802600e2828a2a6c612c1cc8bc
font_01_sfnt_off0000d598.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD598 10984 bytes
SHA-256: e5fbed7b621b813ec176202bab3d3541c726eb9dd72817eec420cd2b27b10e90