Malicious PDF — malware analysis report

Static analysis result for SHA-256 6e883f1aacd67237…

MALICIOUS

PDF

85.8 KB Created: 2021-06-08 02:53:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: 0d6ad9485dd1baa377ee5d3e6580311f SHA-1: 8085f6fab9b8862616d813395a1143f6aab53730 SHA-256: 6e883f1aacd672374a8a89aac6f96a0368e16d661f0b15243b11403585678ed8
126 Risk Score

Malware Insights

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

The PDF was flagged by multiple heuristics, including a critical ClamAV detection (Pdf.Phishing.Trojan-d2568dad23a94d95) and an ML classifier indicating maliciousness. The presence of numerous external URIs, many pointing to disposable hosting and employing UTM parameters, suggests a link farm designed to obscure the ultimate malicious destination. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and a date, indicating it was likely generated programmatically to serve as a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://garglob.ru/pbw?utm_term=vsd+190+pdf+download PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4425759/normal_5fe1b25ea63c3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4389823/normal_6020563d0a18c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4476146/normal_60be795721176.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369777/normal_60692f0ed734c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4499673/normal_605a1c8fcdd7c.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4369187/normal_5feb6ffd88411.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://fubajulak.pbworks.com/f/biochemical_evidence_for_evolution_worksheet_answer_key.pdfIn PDF document text
    • http://pupowivala.pbworks.com/f/vajaminegadamanajat.pdfIn PDF document text
    • http://finebov.pbworks.com/f/wejiruv.pdfIn PDF document text
    • http://poguvovuk.pbworks.com/f/wunexozomalajadebibixuxo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/95b29ab1-3ca4-455f-9a7b-46782b64bc01/que_significa_somos_autorretenedores_de_renta.pdfIn PDF document text
    • http://raravisu.pbworks.com/w/file/fetch/144756273/latitude_and_longitude_worksheets_for_5th_grade.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cd81a0b6-77d8-469a-b24b-32fc35bbcfc6/94333008058.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f45f449a-1052-4c2e-84f5-dc30117be6b8/what_is_learning_and_its_principles.pdfIn PDF document text
    • http://juvupumanut.pbworks.com/f/what_runs_through_cribriform_plate.pdfIn PDF document text
    • http://vimadutukad.pbworks.com/f/rulijusex.pdfIn PDF document text
    • http://pakesobiroge.pbworks.com/f/85206641680.pdfIn PDF document text
    • http://jesababa.pbworks.com/w/file/fetch/144413961/do_graphic_designers_make_album_covers.pdfIn PDF document text
    • http://xibosini.pbworks.com/w/file/fetch/144706575/tiwexefirufuxetusipa.pdfIn PDF document text
    • http://nusometa.pbworks.com/f/52907493738.pdfIn PDF document text
    • http://gitefov.pbworks.com/w/file/fetch/144570165/zinemol.pdfIn PDF document text
    • http://pebakix.pbworks.com/f/word_biblical_commentary_free_download.pdfIn PDF document text
    • http://zemenifinabe.pbworks.com/w/file/fetch/144574800/43272253108.pdfIn 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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fb18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB18 5348 bytes
SHA-256: b221982d65a5ea31bacf92178ea1683fedcdc3cb7ab90d7df80a7b0f3eb2c32c
font_01_sfnt_off00010d76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D76 11252 bytes
SHA-256: c91ead72f14393fa7cb540aa5ba57e78e04a88bf11ac049360c7411f760887cc
font_02_sfnt_off00013437.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13437 16092 bytes
SHA-256: ea75db71c9df7250347a03039f742fcd189f5fc3f08964e696816fa8b5227073