Malicious PDF — malware analysis report

Static analysis result for SHA-256 b331d5f2f3237acb…

MALICIOUS

PDF

84.4 KB Created: 2021-08-08 18:43:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 729d6d42334010ec7b4d8dd72adec07d SHA-1: d191816f49c28d0d00da78c077cdd6172add2a1e SHA-256: b331d5f2f3237acb05000a0c774f9e78258a4c2b4cd9b133a050278c4e0b709a
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many hosted on compromised WordPress installations, indicating a link farm designed to redirect users to potentially malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded links are indicative of a malicious document, possibly leveraging embedded JavaScript for redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://best-turbos.com/wp-content/plugins/super-forms/uploads/php/files/eb6c31c67a7a544232319937b3268c76/lanozarijaso.pdf In PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082398d0c1d7---negawovudu.pdfIn PDF document text
    • https://eobliecky.sk/userfiles/file/98498686456.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160748058c12e8---xufisopat.pdfIn PDF document text
    • https://catherinehourihan.art/wp-content/plugins/super-forms/uploads/php/files/1873feb1c74efd9cdeee8a5d0ce4eb17/pirujuzenuwijowowi.pdfIn PDF document text
    • http://geose.ru/userfiles/file/75155992093.pdfIn PDF document text
    • http://coimbra.hu/uploads/ckfinder/userfiles/files/89651056720.pdfIn PDF document text
    • https://militarynetwork.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16073dedbdb2cd---dokudogupevunafolabinuni.pdfIn PDF document text
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c9343acbba---kirimegawelore.pdfIn PDF document text
    • https://aftaplan.com/works/peepsparty/html/upload_files/file/50023057013.pdfIn PDF document text
    • https://home18.ru/wp-content/plugins/super-forms/uploads/php/files/d5a618f510ece0582e7d82c960f4c2d0/xiwaxajowif.pdfIn PDF document text
    • https://smilepaper.tw/archive/upload/files/44463206590.pdfIn PDF document text
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/16077927ab1f2b---9828877326.pdfIn PDF document text
    • https://valergences.fr/userfiles/file/maxojenefatogamurevelusog.pdfIn PDF document text
    • http://someteme.com/archivos/_20210618185146.pdfIn PDF document text
    • http://nadiadsa.org/userfiles/file/44628189982.pdfIn PDF document text
    • http://maiodi.com/userfiles/files/vonewaleketasafiwewinebi.pdfIn PDF document text
    • http://musikpark-live.de/userfiles/file/roxevivexufuz.pdfIn PDF document text
    • https://iescolumbus.org/wp-content/plugins/super-forms/uploads/php/files/4100c245b970e04a928f5da5e142c3d7/69857232873.pdfIn PDF document text
    • https://noddy.nu/images/file/sovawegu.pdfIn PDF document text
    • http://confidenzacsapagy.hu/upload/45238927538.pdfIn PDF document text
    • https://acornschoolcharleston.org/wp-content/plugins/super-forms/uploads/php/files/56b52ba1dc4abc809816b77868c558ae/davakura.pdfIn PDF document text
    • http://nsdadventist.org/FCKData/file/wiguxiduvepif.pdfIn PDF document text
    • http://anbao.vn/uploads/userfiles/file/12615389208.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=multiplying+fractions+worksheets+grade+5+pdfPDF link annotation
    • http://perfecturology.cafe24.com/upload/editor/imagefile/43430282214.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_off0000e3f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3F1 11416 bytes
SHA-256: 2d91cd28f4a7770ae83afa7aa1e92095b5b80475c70752941f3b65aa3bc7b3c8
font_01_sfnt_off0000feca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFECA 16940 bytes
SHA-256: 0eb8b10aad1115e493bbf81d794a408e0a00d9f67ee62c850aee9383a9db8eea
font_02_sfnt_off00012b63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B63 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1