Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f17536c7742c087…

MALICIOUS

PDF

91.5 KB Created: 2021-08-06 16:28:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 6db7c999a1a282a8b214552112a781bc SHA-1: 39d270224b122407cda9dc506689f2266417b83f SHA-256: 3f17536c7742c087ec45bc2f344003e1eaeab2719c2799a2a4452dbe7a6ddf08
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains a link farm pointing to multiple compromised WordPress sites, which in turn host other PDF files. This suggests a multi-stage attack, likely involving phishing or malware distribution through these hosted documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/16072fe86b3744---11429146391.pdf In PDF document text
    • https://landbondcorten.com/attachment/file/520a0da13cfbd0ce376738cfa6c25b9e.pdfIn PDF document text
    • https://mikepromedia.com/wp-content/plugins/super-forms/uploads/php/files/fivelqvc4fe0j5f8mjvefedmq4/foxap.pdfIn PDF document text
    • https://performanceltg.com/wp-content/plugins/super-forms/uploads/php/files/29c49649f85f38578dd81df639fb0644/fumesop.pdfIn PDF document text
    • http://hz-karavany.cz/ckfinder/userfiles/files/71739067721.pdfIn PDF document text
    • http://agrion.org/upload/fichier/14799184069.pdfIn PDF document text
    • https://www.dekleinewerf.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607b2a4b37d4e---fawariz.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/160c9345c209ea---76952997421.pdfIn PDF document text
    • https://yziact.fr/wp-content/plugins/super-forms/uploads/php/files/sodigta5174bnbjfuqm9ubanl5/vuvekudawagi.pdfIn PDF document text
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608285bf640b9---20316389788.pdfIn PDF document text
    • http://svatba-emi.com/uploads/pages/files/fujekivovev.pdfIn PDF document text
    • http://www.peopleoftheheath.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073ba7618c74---31077789840.pdfIn PDF document text
    • http://scuderieverdina.it/scuderia/userfiles/file/ribaz.pdfIn PDF document text
    • http://simkoongschool.com/uploads/editer/files/koreson.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/jimitupikuvipomorupevipu.pdfIn PDF document text
    • http://weymouthhighschoolclassof62.com/clients/5/50/50fe23896e84432c97ff20d680692bb9/File/74677563470.pdfIn PDF document text
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/r7sjeb46nqmsrd95qhbbp10unh/95245179780.pdfIn PDF document text
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/1608e66b00c46b---86904206186.pdfIn PDF document text
    • https://seataclightingalaska.com/wp-content/plugins/super-forms/uploads/php/files/07ae6a5b4df92e64e065b3ff1fe85fc4/55187060668.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a362d5d61af---xonagigaliwajaf.pdfIn PDF document text
    • https://anthonygillant.com/userfiles/file/fesutipejuseparutufen.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160922efc49288---kofegomapumewoxe.pdfIn PDF document text
    • http://decom.pro/admin/ckfinder/userfiles/files/12655572445.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=what+is+a+running+record+in+child+developmentPDF 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_off000100ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100EF 11120 bytes
SHA-256: 1dd16c4a2a787e91de4d8d1505d07db63959842cc0064a0cb1165c96a816156c
font_01_sfnt_off00011a85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A85 17100 bytes
SHA-256: 51745d3dd7599405c1283321abac889747d428f8738eaa3db3cabffbba07bb1c
font_02_sfnt_off000146e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x146E9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1