Malicious PDF — malware analysis report

Static analysis result for SHA-256 c915a1b8dd856096…

MALICIOUS

PDF

76.8 KB Created: 2021-06-09 09:43:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 0df5ba710025c2c80b8d3f3912729339 SHA-1: eaf72982fbdd84b64a86487c85f51a33141d3292 SHA-256: c915a1b8dd856096e8ce8181f8c51662f52bf410cdd67ad3f35a516d0685cbc6
156 Risk Score

Malware Insights

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

The PDF file contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, suggesting a link farm for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent. Although no scripts were explicitly extracted, the presence of embedded URLs and the overall structure point towards a phishing or credential harvesting attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://synerhu.ru/uplcv?utm_term=fmf+pin+study+guide PDF link annotation
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16088e6e1cbee9---wubukiferu.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/1607690e58af70---39910939597.pdfIn PDF document text
    • http://hoshitorionline.com/uploads/files/65660093.pdfIn PDF document text
    • http://fly.no1-yes.com/userfiles/file/mexubufawuvipekupowati.pdfIn PDF document text
    • http://humanitool.ru/userfiles/file/19756552504.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/abd953d2db14679f8d8fde7de921ebdf/71421041310.pdfIn PDF document text
    • https://messianic.live/wp-content/plugins/super-forms/uploads/php/files/b65d49326047bbd73840a810e90609bb/21946686557.pdfIn PDF document text
    • https://casabresciani.it/uploads/file/95357873000.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/sbm4vulptugts210v7mnrc6911/kegebidetusib.pdfIn PDF document text
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a5f74e3aab---35627421894.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/160b584cb4162a---gugifokeponekatope.pdfIn PDF document text
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071cc7859e2b---texopopifuvepixa.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7c3b05a89---nomekitajidusixugur.pdfIn PDF document text
    • http://plenaadoracao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bc4daca8aa4---vugifumililizi.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160a0e071cfecf---xitage.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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_off0000df98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF98 4852 bytes
SHA-256: 5784fec5c23a77f3fcf3d228648c4d5c494c9e91b18ada6839d8c83b3fc61ec2
font_01_sfnt_off0000f012.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF012 11408 bytes
SHA-256: 0a4e0fdb525c8a4753d9778d2dd1f3c447f05380ffb64c75d0ba0ab48244af8c
font_02_sfnt_off00011700.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11700 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176