Malicious PDF — malware analysis report

Static analysis result for SHA-256 817bdfd52fb8e2b6…

MALICIOUS

PDF

81.7 KB Created: 2021-09-10 21:56:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 4c0fe2930f972ece9c49b9e119811a1c SHA-1: c0b31ca9fbc8b607c34344a476954fb8553a393d SHA-256: 817bdfd52fb8e2b6c4b811fafb7f54bf5b30ef75557acbebd0504f8297d449d4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links, many pointing to compromised websites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. Although no scripts were explicitly extracted, the nature of the links and the PDF structure align with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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 http://stonebreaker.at/kudawema.pdf In PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613af8e421409---siliwopagaginameja.pdfIn PDF document text
    • http://5mal4.de/moneyvidya/web/images/userfiles/file/1828211149.pdfIn PDF document text
    • http://estatepie.com/files/userfiles/file/ligojoledufavomakixul.pdfIn PDF document text
    • https://hasekei.jp/userfiles/file/75508707457.pdfIn PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/161306a58860a9---94376574782.pdfIn PDF document text
    • https://biogenetixpharma.com/ci/userfiles/files/xorixenevesu.pdfIn PDF document text
    • https://typeone.com.my/ckfinder/userfiles/files/69434976988.pdfIn PDF document text
    • http://canadianrockies.ca/files/file/punagokid.pdfIn PDF document text
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/920df6d3cd5fd0b4c9b9f4ae07b2ea3e/81940412452.pdfIn PDF document text
    • http://kingbikeonline.com/images/upload/File/53775036525.pdfIn PDF document text
    • https://rebates.forex/wp-content/plugins/super-forms/uploads/php/files/v6k1mg25a4274vg5rmq08o3rr6/7576568323.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/c649fdf5fcfb9661d0a64aac91dae082/76474623101.pdfIn PDF document text
    • https://radio-clipa.ro/userfiles/file/62459255486.pdfIn PDF document text
    • http://apicn.net/upload/files/81492466103.pdfIn PDF document text
    • http://criminisiepartners.it/userfiles/files/rekogogabufelovu.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133dbc64685f---68504445083.pdfIn PDF document text
    • http://hyunsin.net/userfiles/file/zupax.pdfIn PDF document text
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/79qud17jknvj13kju1sf6m1a36/ribonojod.pdfIn PDF document text
    • http://arredamentoambienti.it/img/file/zukikexobup.pdfIn PDF document text
    • http://h-p-n.fr/catalogue_dynamique/file/21140739646.pdfIn PDF document text
    • http://www.espaciocultivarte.com/ckfinder/userfiles/files/sutuvesur.pdfIn PDF document text
    • http://pobierzplik.pl/uploads/files/manit.pdfIn PDF document text
    • https://educhina.mn/editor/files/21287459106.pdfIn PDF document text
    • http://elite-nails.pl/Upload/file/5603508309.pdfIn PDF document text
    • https://wedding-photos.cz/userfiles/file/1127471117.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=asphalt+8+old+version+apkPDF 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_off0000d8c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8C6 18412 bytes
SHA-256: 2bd5994fb1a0930102235631bb0878266ad5bf282dc8a872793393e8d31654dc
font_01_sfnt_off000107ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107EA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012001.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12001 10836 bytes
SHA-256: 1a0556e871a807266610fe783b2d2a4a5d891e4eb2fdd7017b37016457066de0