Malicious PDF — malware analysis report

Static analysis result for SHA-256 741691d3cf5ce32a…

MALICIOUS

PDF

83.1 KB Created: 2021-09-15 19:53:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 2e20bae3b1b9b26df7da0a2a29eafe89 SHA-1: 369a6b1e25d13e88b310caf6799db0a689681695 SHA-256: 741691d3cf5ce32a8563bcd5ad7b15619afc3100ddc0af3f0a64f0ddf8e03355
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised WordPress upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of external URI heuristics and the 'PDF_SEO_DISPOSABLE_LINK_FARM' rule further support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://irlanc.ru/uplcv?utm_term=ludo+star+2+mod+apk+unlimited+coins PDF link annotation
    • http://niszczeniewaw.pl/userfiles/file/76625550529.pdfIn PDF document text
    • http://zechnerbau.at/images/content/files/vorozotizewoju.pdfIn PDF document text
    • http://jumpstart.mobi/userfiles/file/kukulexumamo.pdfIn PDF document text
    • http://timnhanhonline.com/upload/files/13281852691.pdfIn PDF document text
    • https://genegurumiraclehealer.com/userfiles/file/38668561904.pdfIn PDF document text
    • https://edubox.mn/uploads/users/0/files/doxek.pdfIn PDF document text
    • http://www.sname.org.tw/sname/ckfinder/userfiles/files/jonijazuw.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1613ae41f132b2---xudazat.pdfIn PDF document text
    • https://autopits-directo.migrupoq.com/ckfinder/userfiles/files/pelupogodixuxela.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613810417bc96---94324640279.pdfIn PDF document text
    • http://littlepearlspublishing.in/data/eimages/file/doroxemexebufuvenumegorew.pdfIn PDF document text
    • http://yamamatoen-wanwan.jp/ckfinder/userfiles/files/10016622419.pdfIn PDF document text
    • http://pescepiana.eu/userfiles/files/renanovogexiw.pdfIn PDF document text
    • https://stka.gr/ckfinder/userfiles/files/varopusulogejixadobakikok.pdfIn PDF document text
    • http://tubesealer.com/uploaded/file/9132852166137d0f5abe7c.pdfIn PDF document text
    • http://www.sushmitamukherjee.com/fckimages/file/kovumebuvobobozafijukaw.pdfIn PDF document text
    • http://resumesfromabove.com/userfiles/file/wunededituwito.pdfIn PDF document text
    • https://royal-art.pl/uploads/userfiles/files/88448251671.pdfIn PDF document text
    • http://elosc.com/upFile/file///ITX202109020400475920.pdfIn PDF document text
    • https://tiemhoamo.tiemhoahaibara.com/data/dulieu/files/36059822964.pdfIn PDF document text
    • https://marblobaths.com/app/webroot/img/files/virepudokenazakupifarulop.pdfIn PDF document text
    • https://salondumariagededijon.com/userfiles/file/miwezesaliv.pdfIn PDF document text
    • http://cuspsurgeons.com/userfiles/file/wemebub.pdfIn PDF document text
    • http://christembassydocklands.org/wp-content/plugins/super-forms/uploads/php/files/b4adf6eb019e80268188e50aef3d634b/26685615452.pdfIn PDF document text
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613567026deac---bufapesew.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_off0000db01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB01 19592 bytes
SHA-256: 71fdda5013c241783f03b4693efa928fcb62ade121354cc529a477fe66d63351
font_01_sfnt_off00010d98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D98 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000125af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125AF 10944 bytes
SHA-256: 2c2128281e1912df3efea5be89884bc50851ac1490f1456680b1cfcd277ac8a9