Malicious PDF — malware analysis report

Static analysis result for SHA-256 28276acbffb6fd8d…

MALICIOUS

PDF

81.2 KB Created: 2021-06-18 04:26:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 708672f3cad7a7d8eb55fd987f38d531 SHA-1: 5ff3fb79ea9c8fbc5d5f159e7c366aacc810b7d0 SHA-256: 28276acbffb6fd8d3107514c3d0225205d2d8f4e93660f4254ccfa7129930460
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a phishing or malware distribution campaign, likely initiated via spearphishing.

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 http://brighterhealthcare.co.uk/wp-content/plugins/super-forms/uploads/php/files/80utbh0kvc07v8fp5md4f40dt3/gunipini.pdf In PDF document text
    • http://morgancountyoh.com/userimages/53769191823.pdfIn PDF document text
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/83f94147ce52d1ca537d4b38adae42b4/83818772634.pdfIn PDF document text
    • https://chefinhogourmet.com/wp-content/plugins/super-forms/uploads/php/files/0d449a68b675090f7d76ca1ad647bf6b/javoretorigexadakozeg.pdfIn PDF document text
    • http://sumnerclassof1976.com/clients/4/49/49b54eafcc86ae0c30eb104ab8b91c7c/File/78667497815.pdfIn PDF document text
    • https://www.apartamentselsllacs.com/wp-content/plugins/super-forms/uploads/php/files/51r0l7cns3prn2b8qhkn2rtgc0/57110460324.pdfIn PDF document text
    • https://www.cittadelmiele.it/wp-content/plugins/super-forms/uploads/php/files/695f648b60051d1039e1b2fefee3baa7/supur.pdfIn PDF document text
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/74af2ba096783efc78cb4a24f5f5eda2/49014783637.pdfIn PDF document text
    • http://ar-intl.net/wp-content/plugins/super-forms/uploads/php/files/iqefrkotis85jr26pkl0sf7lq4/jofotitobijinemexujo.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/160bc25cfc8772---wanodibosamu.pdfIn PDF document text
    • https://carlojans.com/cms/file/toreserilitedim.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1609e104411026---boweba.pdfIn PDF document text
    • http://sklepjola.pl/userfiles/file/binepudegome.pdfIn PDF document text
    • http://euro-ex.net/images/blog//file/6154917989.pdfIn PDF document text
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c93383c8035---lamupibanobugeluvuzoz.pdfIn PDF document text
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/160b8b75ac9c9b---53328725205.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/160750736ab3f8---bililaxupezoxet.pdfIn PDF document text
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/gjpi3461ap1l50as3ibhucdtml/52414729115.pdfIn PDF document text
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c70efb14df6---risogiveselezagubaga.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/cv9VXjIrmdE/uplcv?utm_term=how+to+get+infinite+money+gta+5+onlinePDF 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_off0000fd13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD13 5092 bytes
SHA-256: ffb41ad66b804a118e9b9b610072a7834d00d849827e8fdbf36e3c77896c7e62
font_01_sfnt_off00010e7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E7D 11480 bytes
SHA-256: c0527a0f368c69d64c7e745a65e398c803916ceea742e7ed3a2788aed483a9e9