Malicious PDF — malware analysis report

Static analysis result for SHA-256 938861a67fa15d55…

MALICIOUS

PDF

75.2 KB Created: 2021-09-11 16:26:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 9871559a1562ef6baa39200df037279c SHA-1: bee142f698b4f11d3ffcffb440660921db5ea39d SHA-256: 938861a67fa15d553c392e23ab2115bbad3249f2c49184346dfc31f3f40dfbde
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm or phishing lure. ClamAV and an ML classifier flagged this file as malicious, specifically as a phishing trojan. The presence of multiple external URIs and link farms indicates an attempt to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613b3089a3db6---27854191321.pdf In PDF document text
    • https://sedefartphotography.com/resimler/files/buneduboku.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/161327cdf66cbb---ligoxomevop.pdfIn PDF document text
    • http://thietbimaugiao.vn/Images_upload/files/pojejiremiguxaxadotakub.pdfIn PDF document text
    • http://swissies.lt/ckfinder/userfiles/files/vokugusukugefa.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613784dbdcaf1---16386831814.pdfIn PDF document text
    • http://mrspk.com/ckfinder/userfiles/files/85929908433.pdfIn PDF document text
    • http://teamwork-poetschke.com/ckfinder/userfiles/files/fonatatup.pdfIn PDF document text
    • http://ebd.su/UFD/7623/files/13394571083.pdfIn PDF document text
    • https://ngoctraithaibinhduong.com/uploads/news_file/13907958374.pdfIn PDF document text
    • http://tea-ra.com/user_data/upload/save_image/files/2907774859.pdfIn PDF document text
    • https://festivalecolo.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613215a33744e---82152597335.pdfIn PDF document text
    • https://portalkucharski.pl/app/webroot/media/files/rugapen.pdfIn PDF document text
    • http://studiotecniconuti.it/userfiles/files/73771617981.pdfIn PDF document text
    • https://mygenius.ru/admin/ckfinder/userfiles/files/dabokadazedava.pdfIn PDF document text
    • https://iringmalaysia.com/ckfinder/userfiles/files/nobaxikuxedaxi.pdfIn PDF document text
    • http://rabotatver.ru/userfiles/admin/mivoravi.pdfIn PDF document text
    • https://chuyennhakienvangvn.net/upload/files/gamikuvofimeragafikur.pdfIn PDF document text
    • http://zubrcup.by/files/files/34687847224.pdfIn PDF document text
    • https://functionalmovement.gr/wp-content/plugins/super-forms/uploads/php/files/a5278c92c334ea828f3d60826d2d1a5a/levafavuzevizodigug.pdfIn PDF document text
    • http://ubest.ru/images/file/35019267879.pdfIn PDF document text
    • http://rsst77.ru/upload/files/xoluwogafunomudoxu.pdfIn PDF document text
    • http://www.sospapa24.com/lib/ckfinder/imgupload/files/14613384480.pdfIn PDF document text
    • http://silesiacapital.eu/data/file/80568290823.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=equation+for+a+quadratic+graphPDF 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_off0000c35a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC35A 10780 bytes
SHA-256: 03a26c305e31e672cec33c445f5cca3765e60c8cdefac1df2a044f2c40c05e4f
font_01_sfnt_off0000db89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB89 17140 bytes
SHA-256: 49ad741b31d90ab7ff11146205097c344733040ba87844711c2ac39f075e7bc8
font_02_sfnt_off000106ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106FF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1