Malicious PDF — malware analysis report

Static analysis result for SHA-256 4304d035415b3a64…

MALICIOUS

PDF

81.9 KB Created: 2021-09-09 05:24:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: c3386fe3fd167b65efc1341b4f26d68c SHA-1: f8bece45fa4e44864f58ed357aad8bf2d386b6f3 SHA-256: 4304d035415b3a648b44352263cf1a77ffd85353dc2fcfd9b069fb8da7f746d5
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. The heuristics indicate it functions as a link farm, with numerous external URIs pointing to potentially disposable hosting. While no scripts were explicitly extracted, the PDF structure and the presence of many unknown URLs suggest an attempt to redirect users to malicious sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://adurucui.com/ckfinder/files/nelasasobiziwomesepuj.pdf In PDF document text
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/0ff0c754e4afb20f5401ef059c04bf1e/peroneponasedevanigin.pdfIn PDF document text
    • http://www.biogreeno.com/cms/ckfinder/userfiles/files/sivenena.pdfIn PDF document text
    • http://dissanna.com/temp/fckeditor/file/nupenesixefo.pdfIn PDF document text
    • https://basundharamart.com/userfiles/file/86008333104.pdfIn PDF document text
    • http://sun-tes.ru/files/file/50478262126.pdfIn PDF document text
    • http://gesundimjob.at/images/content/files/lupewuwiboguva.pdfIn PDF document text
    • http://ville-dammarie.com/ckfinder/userfiles/files/perabixoxomerip.pdfIn PDF document text
    • http://rioairporttransfer.com/ckfinder/userfiles/files/tojokifegow.pdfIn PDF document text
    • http://dientrotiendathc.com/media/ftp/file/xobup.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16134c43b04ab1---98366137864.pdfIn PDF document text
    • https://cottonweb.net/userfiles/file/pinarenanibasawogozuf.pdfIn PDF document text
    • http://co-wemart.com/careeruserfiles/file/75545272518.pdfIn PDF document text
    • http://debeight.net/UserFiles/File/fojiv.pdfIn PDF document text
    • http://www.css-jp.com/upfile/files/2021/09/06/bexit.pdfIn PDF document text
    • https://www.icicle-mountaineering.ltd.uk/ckfinder/userfiles/files/57120678545.pdfIn PDF document text
    • https://polaria.cz/images/file/27823909010.pdfIn PDF document text
    • http://resortcrimea.com/ckfinder/userfiles/files/juxunesoxugekiborexasor.pdfIn PDF document text
    • http://lasermedia.cn/userfiles/file/mugopagexeko.pdfIn PDF document text
    • https://pianotuningdarwin.com/userfiles/files/kupenavudujelax.pdfIn PDF document text
    • https://onderhoudnlgarantie.nl/upload/file/82525240694.pdfIn PDF document text
    • http://www.tramag.pl/upload/file/63010866281.pdfIn PDF document text
    • https://barrier.exma.cl/ckfinder/userfiles/files/disugurojerumewetobuwi.pdfIn PDF document text
    • https://eldorado777.ro/upload/editor/file/61771274883.pdfIn PDF document text
    • http://bookblog.kr/data/file/files/tubefeki.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=best+free+editor+for+androidPDF 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://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_off0000de06.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE06 17056 bytes
SHA-256: 2d1e3cf9a05b44f663c92fbd99905681c42ad584d0351a9e024842fc2024f1de
font_01_sfnt_off00010a25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A25 10352 bytes
SHA-256: 6b73e5e1880b257989b4e8e99d67407c0b6c356304301982e72f26e1885bd47d
font_02_sfnt_off000121b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121B0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1