Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca43e933e47c116f…

MALICIOUS

PDF

74.6 KB Created: 2021-06-08 21:06:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 93c8356e795263dcc1d7b2a3c42045d6 SHA-1: 9dc46b93909bfe4d295b94bcfd2ff2dc3c5ff29a SHA-256: ca43e933e47c116f15fede74194d914eb97b2c60eacddff3e578c7631a0cc8c5
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 appear to be hosted on compromised WordPress sites 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 PDF structure and embedded URLs are indicative of a malicious document, likely delivered 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 https://krisoc.ru/uplcv?utm_term=ms+round+plate+weight+calculation+formula+pdf PDF link annotation
    • http://www.dj-csnl.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160936b2cb00f1---wuvolipa.pdfIn PDF document text
    • http://axiomestates.com/userfiles/file/buviketokalat.pdfIn PDF document text
    • http://abogadosaguilar.com/ckfinder/userfiles/files/19797815995.pdfIn PDF document text
    • https://best-turbos.com/wp-content/plugins/super-forms/uploads/php/files/2f0e1c1cea1fb45439f495f1e8932621/68931386676.pdfIn PDF document text
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4cc57154ff---31995604276.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609005f12895a---potugofaso.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/udksglshghlnv7gbpklj1efla7/ziguf.pdfIn PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/9ff3d1f830ec07b84e32c6f207496544/92479590545.pdfIn PDF document text
    • https://astek-telem.fr/userfiles/file/47901213978.pdfIn PDF document text
    • https://deniz-sogutma.org/img/userfiles/file/vaxobefobogir.pdfIn PDF document text
    • https://poolpoint.be/uploads/file/18610126474.pdfIn PDF document text
    • https://foxtailmag.net/wp-content/plugins/super-forms/uploads/php/files/f066cb364ea4260e2e081a661a1b8ffc/36051557018.pdfIn PDF document text
    • http://modnyi-buket.ru/uploads/files/5474336093.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/71rgfdrl8i30imf2jq7a3cgdv1/32071139794.pdfIn PDF document text
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2f16a7b9d3---junulerumi.pdfIn PDF document text
    • https://legacyltg.com/wp-content/plugins/super-forms/uploads/php/files/7423f82c2ac6119defb717131a80ddca/86886276502.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_off0000d503.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD503 5548 bytes
SHA-256: ed22a6638f1da15c518f5dd177c2ccf5a28b9991491be4a165c921bfca93587b
font_01_sfnt_off0000e7d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7D4 11568 bytes
SHA-256: 2dd2a4cced779024212dae3e8f846d05ea9b3be1bcebe8f9135ff0dbf89a2a94
font_02_sfnt_off00010f2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F2D 4324 bytes
SHA-256: b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c