Malicious PDF — malware analysis report

Static analysis result for SHA-256 cfcdfd643f7af832…

MALICIOUS

PDF

168.1 KB Created: 2021-08-14 05:32:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 236a0c98eb077cb8a9aa063616318d1e SHA-1: f469250d7bf49321e9c3952d2f712e3d27005250 SHA-256: cfcdfd643f7af832b9a8eb4a74d50d6d43f84ce3f400016083ed37366a5ff64e
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised or disposable domains. The presence of numerous PDF links and the ML classification suggest an intent to distribute malicious content or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9457

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://groupunsur1.com/contents//files/sufepu.pdf In PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adbedeb12c2---wefemakole.pdfIn PDF document text
    • https://liur-krd.ru/userfiles/file/kojuzikirimogol.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/2f4523fbb344f758e1ee631a3adb4678/14232587010.pdfIn PDF document text
    • http://www.pvvc.cz/files/tujaniwafuxuvapaf.pdfIn PDF document text
    • http://cristal-in.fr/userfiles/file/ziseralonewar.pdfIn PDF document text
    • http://alliusie.com/userfiles/file/feguk.pdfIn PDF document text
    • https://ahreco.com/uploads/news_file/pewetugiju.pdfIn PDF document text
    • http://qbcar.ru/ckfinder/userfiles/files/73442617810.pdfIn PDF document text
    • https://cullinanconstruction.com/wp-content/plugins/super-forms/uploads/php/files/jro20gguj7vnkudpt4g377pten/8281996845.pdfIn PDF document text
    • http://xn--clinicaquirogavilario-vbc.com/wp-content/plugins/super-forms/uploads/php/files/9f57757g8crn2dimjinmrhfq37/gakilugelezobaxokasekaj.pdfIn PDF document text
    • https://canvasations.com/wp-content/plugins/super-forms/uploads/php/files/6b7aa1bo760jaocaurbk07cp64/bemud.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078e5d4d3606---86428585693.pdfIn PDF document text
    • http://sh-songshi.com/admin/upimg/file///44209760962.pdfIn PDF document text
    • http://www.cpnatacao.pt/backoffice/ckfinder/userfiles/files/6220773410.pdfIn PDF document text
    • http://www.socalgreatwhite.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073e54f30f52---lexidabe.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/68671588565.pdfIn PDF document text
    • https://designclarf.it/file/vepesuganakiga.pdfIn PDF document text
    • http://redeyeldn.com/userfiles/file/18832002858.pdfIn PDF document text
    • http://drlalashow.com/php/billboard/uploads/file/7177677922.pdfIn PDF document text
    • https://akapacha.com/userfiles/file/topadobipumut.pdfIn PDF document text
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6874e35c28---tisoxegufok.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/v5qdh8332u74eispi3nvoavss4/56302242016.pdfIn PDF document text
    • https://lostsoulsmemorialnj.org/wp-content/plugins/super-forms/uploads/php/files/a787dda1409e6d6dedbb8278a561c0e9/72300857766.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=libro+de+matematicas+1+de+secundaria+2019+santillanaPDF 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_off000223fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x223FB 22092 bytes
SHA-256: 6bec557cbd054b0aa697c07012b0aa8432a5194cf0246ff119cd42d3fc681931
font_01_sfnt_off00025c78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x25C78 11188 bytes
SHA-256: f31c297e16d82824d5d06692b9f68f6d3f01b8020f009636c1da571f74a857ca
font_02_sfnt_off000276b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x276B6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1