Malicious PDF — malware analysis report

Static analysis result for SHA-256 e2a78afcd79743c4…

MALICIOUS

PDF

86.3 KB Created: 2021-06-09 08:37:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 4f6597ca1564978ab57f57136a06d4f7 SHA-1: 717ab137d8feeb0cb8ec4c1b55c3862d92454449 SHA-256: e2a78afcd79743c4746c122e3955477a49c56aeeff629a912b7503293942dd76
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file is identified as malicious by ClamAV and an ML classifier, with multiple heuristics indicating it functions as a link farm. Several embedded URLs point to compromised WordPress sites and disposable hosting, suggesting an attempt to redirect users to malicious content. The document body, though heavily obfuscated, contains metadata related to its creation, but no direct instructions or lures are discernible.

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=organic+chemistry+class+12+chapter+name PDF link annotation
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/9ced5920e8b3e35c993dc0300aa4c7a8/witovixugisafibijukobu.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/larelulewinive.pdfIn PDF document text
    • http://alexlunacoach.com/img/editor/file/tuferutitib.pdfIn PDF document text
    • http://degrossier.nl/uploads/file/20212699275.pdfIn PDF document text
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d1c6d596f3---bujagobidig.pdfIn PDF document text
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a6b77a5c958---kalitebo.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1608ee6fb34ec9---dixevunolawoza.pdfIn PDF document text
    • https://amenajarisiconstructii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16090ca47f41b9---82651682526.pdfIn PDF document text
    • http://esipro.fr/userfiles/file/pufiz.pdfIn PDF document text
    • http://vdgairconditioning.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b00ca5dce58---lalujukewufodudazedi.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/1608ef0c7ceda5---xopovirikisik.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/de9od1hgtklufe77svm5j1dnjt/28370392247.pdfIn PDF document text
    • http://taxicityplus.ru/userfiles/file/44837306559.pdfIn PDF document text
    • http://www.grundys.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607325218e195---27658779598.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1608b4e238e94b---31877946849.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_off000107c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107C4 5336 bytes
SHA-256: 46faa3337d016767e43e4f530b1bd15aabfb45ac35ec3d136fde72a362bb6351
font_01_sfnt_off000119c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119C4 10496 bytes
SHA-256: dd42fbe42bd44ddfd5006ed7d89f1250ccf673f3666fd15f4aa30064c816b961
font_02_sfnt_off00013d9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D9A 4324 bytes
SHA-256: ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3