Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f62fd3937d981cd…

MALICIOUS

PDF

88.7 KB Created: 2021-06-16 21:24:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-01
MD5: 922d01fe40dd379ad5f2e168ecf6ff8f SHA-1: 7163509c433d90e457cbbb756082dfc200ffb45c SHA-256: 3f62fd3937d981cd0a1152331b952aa7d7b46c557e40839d75b42670ab791e61
156 Risk Score

Malware Insights

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

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. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://synerhu.ru/uplcv?utm_term=science+and+maths+quiz+questions+and+answers+pdf PDF link annotation
    • https://homini.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1608f3172b3316---wigawuziripozaramegoba.pdfIn PDF document text
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/k631lcpgotstuupsddh4fqag96/49158067294.pdfIn PDF document text
    • http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160b91e0306b34---lewixagoturubuwat.pdfIn PDF document text
    • http://mazurubezpieczenia.pl/zdjecia/fck/file/46687917645.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/16079c468363f0---kapelumedidenojobodifobo.pdfIn PDF document text
    • https://whiteelephant.co.in/wp-content/plugins/super-forms/uploads/php/files/6fd02a0f8b6cf2c0e5f8454f19740fb5/jupogax.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/16072cb5347087---27438605925.pdfIn PDF document text
    • http://reanda.com/jingkelun/userfiles/files/20210608195744.pdfIn PDF document text
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c89860e0d5c---73714439382.pdfIn PDF document text
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/dvi48apislvopep0dmgdulhltu/doruwurem.pdfIn PDF document text
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/vk1i4q7tfsuia5gheebnn871rb/13096990617.pdfIn PDF document text
    • https://aslimitada.com/userfiles/file/mobokenibedel.pdfIn PDF document text
    • https://canvasations.com/wp-content/plugins/super-forms/uploads/php/files/mnb2n5jiqpc51e3k7b5nfo7h06/vireroxonovifotu.pdfIn PDF document text
    • http://clinicacomciencia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a88d452768e---58037201938.pdfIn PDF document text
    • https://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6a6b0dfb48---zajosopobanirowoxesarojun.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000110e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110E8 5736 bytes
SHA-256: 2db0ea9d788e43cc259f9a6fe16be01e0d03336f6c9c0325f2dd6d78f85204af
font_01_sfnt_off00012457.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12457 1728 bytes
SHA-256: 8a7fef30536efc43730865987e3b75d47a259a08003b22921e980fc4baa691d2
font_02_sfnt_off00012cf2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CF2 11736 bytes
SHA-256: ba7822237e59c041b378b9589df663fe10e680d0db3ec306162adac5122cf61e