Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a31c51be8753103…

MALICIOUS

PDF

78.6 KB Created: 2021-06-11 04:47:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 54ee396e216368d1dde7204dfa9e6a83 SHA-1: de3d0bbd41a3dcd8bddbe362ce339f3b8d5ed15a SHA-256: 4a31c51be875310309f44ed9aa6b9e8d6bbe8402d614712af8c2b9e281db734c
156 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. 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 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://nomylo.ru/uplcv?utm_term=surface+area+and+volume+class+9+all+formulas+pdf PDF link annotation
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/03bbd749df1f858dcc078cf0f16ac239/lafesemubotuferewo.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/342da07841b66564b9bb6b9281b5582c/fipebafifikolozeve.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c97df69b62---14893954130.pdfIn PDF document text
    • https://christianboudreau.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071341b6404f---82523266082.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/16073af246bb91---jesomegoxawi.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/3ftaaqci8nq4cucfurpb8cs10e/11523699306.pdfIn PDF document text
    • http://accessprecision.com/userfiles/file/xexavame.pdfIn PDF document text
    • https://www.tanyadantus.com/wp-content/plugins/super-forms/uploads/php/files/914908d081476eb00768f0df6e865c78/sevigix.pdfIn PDF document text
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/c16d0a93e209c5cbdd0456ae2ceb0a79/32481013528.pdfIn PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/160805d23009bb---nubamiromivev.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b45be28bbb3---tabat.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/160ae291fbc22a---40662856455.pdfIn PDF document text
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/160947d3052be0---komojiwupunaliz.pdfIn PDF document text
    • http://xn--e42bt3l.net/upfile/files/75264686391.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_off0000e791.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE791 5376 bytes
SHA-256: f0c1e6717467642a6e5465e4315464e7410d3f7ca0cfa0719011836b4f76d24f
font_01_sfnt_off0000f9b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9B2 11056 bytes
SHA-256: 241dd1d0b8e769258d476c8b6d20383e39fd9eb2b58714acc897b2438c808aa8
font_02_sfnt_off00011f22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F22 4324 bytes
SHA-256: d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378