Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb4aa5282d99f487…

MALICIOUS

PDF

91.0 KB Created: 2021-08-05 09:09:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: c4fa9c71e0181937af98ec6e68732d7a SHA-1: ac355d666922c4d76ba4fb0ec5f8441976e3600e SHA-256: cb4aa5282d99f487cf65eac260f326435fbd083be52837f3ca72549509108528
156 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan. It contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics indicates a strong intent to direct users to external, potentially malicious, content. No scripts were extracted, but the overall structure and heuristics point towards a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

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://medvor.ru/uplcv?utm_term=plane+simulator+unblocked+games PDF link annotation
    • https://mvpartners.be/images/uploadedimages/file/69973240820.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/ioce2rh8epu64ob8mk01io66n7/ledavuvakimobalufilar.pdfIn PDF document text
    • http://agendaalzheimer.org/files/galeria/files/20042701580.pdfIn PDF document text
    • http://chickendaylacrescenta.com/uploads/files/18342005237.pdfIn PDF document text
    • http://zoncmswebsitebeheer.nl/files/editor/file/givigazepaxanozezowito.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607c93acc1519---63549960573.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608105a8c84dd---38011884506.pdfIn PDF document text
    • https://refour.eu/wp-content/plugins/super-forms/uploads/php/files/b76ae88974dfa38f44168eb3ab7b289b/18319478358.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c497b47b24---somunetovigu.pdfIn PDF document text
    • https://fajndoktor.cz/images/file/files/6567253779.pdfIn PDF document text
    • https://shinyjewellers.com/wp-content/plugins/super-forms/uploads/php/files/8dtspp1qr3ki1i12kf87c26b44/72082521453.pdfIn PDF document text
    • http://altaprecision.com/userfiles/file/budatawagevov.pdfIn PDF document text
    • https://4of100churchstreet.com/assets/media/files/keriwuxebupodawiwimin.pdfIn PDF document text
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5a28a92dd4---60457080029.pdfIn PDF document text
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/jr1iqkjqciharfdft6mch3203d/5243995075.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/jimek.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070dd9b1ba62---6074387414.pdfIn PDF document text
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081b951dea17---78069296364.pdfIn PDF document text
    • https://vegastel.eu/components/com_mijoshop/opencart/image/data/files/61707302961.pdfIn PDF document text
    • https://klubkanine.com/home/klub/public_html/ckfinder/userfiles/files/sovokanujokuzem.pdfIn PDF document text
    • http://modnyi-buket.ru/uploads/files/45252856766.pdfIn PDF document text
    • http://mientrungpetrohotel.com/users/files/28963401331.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_off0000fee0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEE0 17096 bytes
SHA-256: e09180f8452ed61dcc8d65611abee4be445b1c37a301e1c0c1d1ed2619eec6db
font_01_sfnt_off00012b53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B53 11044 bytes
SHA-256: 6b1aac43c2594d2a06608a9c9405144b7d65ba5c15765027bd8fd676b6e711af
font_02_sfnt_off000144d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x144D7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1