Malicious PDF — malware analysis report

Static analysis result for SHA-256 a19c8b6e8f1f66da…

MALICIOUS

PDF

88.3 KB Created: 2021-10-05 19:08:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 41ca51487c26c700dabe5d2b9a87e9ce SHA-1: 551932482ce8dd2392c05c5838c71da9f391b9af SHA-256: a19c8b6e8f1f66da578970a8c265d3dd3114a6f01c1931527c423fe73c17e276
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to disposable domains, indicative of a link farm designed to host malicious content or phishing pages. The ML classifier and ClamAV detection strongly suggest malicious intent, with the PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically identifying this pattern. While no scripts were directly extracted, the structure and URL patterns are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://nomylo.ru/uplcv?utm_term=dolly+parton+on+colbert+show PDF link annotation
    • http://rudolphi.nu/userfiles/file/bepomonofurajijogubex.pdfIn PDF document text
    • https://perfecthospitals.com/FCKeditor/file/rusudefubetirijawamu.pdfIn PDF document text
    • http://garmaclima.com/uploads/ckfinder/files/damewitigagakalejelugev.pdfIn PDF document text
    • https://rsvforum.com/userfiles/file/43672769774.pdfIn PDF document text
    • http://biznesfishki.ru/files/userfiles/files/28800998920.pdfIn PDF document text
    • http://autodilygood.cz/files/file/lezabovisarexezomag.pdfIn PDF document text
    • https://belitour.ir/basefile/belitourir/files/xafarinoxa.pdfIn PDF document text
    • http://fewo-spreewald-schoetzigk.de/brandenburgtag/img/editor/file/76730000174.pdfIn PDF document text
    • http://letresorellebio.it/userfiles/files/60599794450.pdfIn PDF document text
    • http://ipceurope.com/assets/file/19534148115.pdfIn PDF document text
    • http://qianlong99.org/ckfinder/userfiles/files/74394602269.pdfIn PDF document text
    • http://tarasovfabrika.ru/uploads/file/papexozojasitozafame.pdfIn PDF document text
    • http://kompassztuki.pl/Image/files/tekazesul.pdfIn PDF document text
    • https://scalper.ir/data/files/file/sisuzim.pdfIn PDF document text
    • https://merohamro.com/ckfinder/userfiles/files/13264631281.pdfIn PDF document text
    • http://pferdefreunde-brueckenhof.de/sites/default/files/userfiles/file/16682213901.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613ae2dd125c4---muzujitirogiluwu.pdfIn PDF document text
    • http://ambvet-trefontane.eu/userfiles/files/vosafevuvakozefudo.pdfIn PDF document text
    • http://tzsunup.com/upload/tozasavibesefilezovamo.pdfIn PDF document text
    • https://wmu24.ru/media/file/polagoxujuwekasowub.pdfIn PDF document text
    • http://grafosaleservice.cz/images/fck_editor/file/25338832703.pdfIn PDF document text
    • http://opgzvh.hr/upload/file/59720619772.pdfIn PDF document text
    • http://shopabrang.com/images/files/28468897195.pdfIn PDF document text
    • http://adec-interiors.net/Uploads/file/43827733035.pdfIn PDF document text
    • https://www.highlandernepal.com/assets/ckfinder/userfiles/files/kitafufizuxotitejaziru.pdfIn PDF document text
    • http://tctrack.vn/images/newtech/files/3315692489.pdfIn PDF document text
    • http://kimsanghun.com/upload/userfiles/file/2021961131343081.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://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_off0000ed85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED85 10720 bytes
SHA-256: 475953a7d4584a50a29caf2d18c1d34a8ade4b1b4d802fb5eacbe3868389642c
font_01_sfnt_off000105fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105FB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011e0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E0D 20448 bytes
SHA-256: 5e2eff4593200d6410ed6aba33ff03de4ac76d7e099f393526e0715e9a1aaa39