Malicious PDF — malware analysis report

Static analysis result for SHA-256 281615cbce651ecc…

MALICIOUS

PDF

80.6 KB Created: 2021-06-23 10:51:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-01
MD5: 7e29302d2925c9cf2d1ebbd7ebf67e8d SHA-1: 24cc01a4e6e4e059dccf4be92a6fdc4a4e5d64cc SHA-256: 281615cbce651eccd1d7a8f3c48cd8d7e5b5d75d62764a44bf09a54cd7c0fbbd
164 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. It uses an invoice-themed lure. 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 0.9998

Heuristics 7

  • 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.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/3l8jbouacla5q9r7eo7ht5okuv/xefovub.pdf In PDF document text
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/160a31198d4a61---getekel.pdfIn PDF document text
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/64489c95006601efe4bf8eca6611cc4a/julipubuxiwivexoku.pdfIn PDF document text
    • http://s8radziejowice-paszkow.pl/userfiles/file/28066767728.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/16097bab9aa61d---lufegeg.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608e4eecbabcc---fuvilonugoguwe.pdfIn PDF document text
    • http://aivieksteslaivas.lv/userfiles/file/wabilavomusajanuwozuwuti.pdfIn PDF document text
    • http://thaoduocquyhiem.com/userfiles/image/file/xetajamixalasafuruxokif.pdfIn PDF document text
    • https://chmelo.hu/sites/default/files/file/90182205197.pdfIn PDF document text
    • http://xn--e1aazeoc7d.xn--p1ai/images/shared/file/51205746418.pdfIn PDF document text
    • http://agriturismocorteerbatici.it/userfiles/files/54941652647.pdfIn PDF document text
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/9e48566c9b23b42d0af279e9a22bc5b4/pubijozujubotono.pdfIn PDF document text
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a3b2b72ff14---wamexazibenezuruvunemazu.pdfIn PDF document text
    • http://khiconghoixuancong.com/Khicong/admin/userfiles/file/xabowiferefi.pdfIn PDF document text
    • https://www.masismarketing.com/wp-content/plugins/super-forms/uploads/php/files/041f136cf50fb0d041b99651338fc316/35310334679.pdfIn PDF document text
    • http://tantex.org/tantex/tantexuserfiles/file/jadepowatojukiluroza.pdfIn PDF document text
    • http://thegioidahoacuong.com/uploads/image/files/78888771045.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/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=form+quotation+excelPDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f4f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4F1 4916 bytes
SHA-256: ebe5e1f067244e83b5974f5123094acd657ede56de88c2b9384eff5b3bbd7c65
font_01_sfnt_off00010594.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10594 1800 bytes
SHA-256: e9a5a1f6ed95b1e3669933bb00002ad32a1708c3e0b735191cad5e02368a6c7d
font_02_sfnt_off00010e22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E22 11500 bytes
SHA-256: 4f44f1a04b7ecf76869d15c2438794ee5aa9e117c17f0f9e1f95c113c1a91c08