Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d4fbc6e7037a96d…

MALICIOUS

PDF

83.9 KB Created: 2021-09-20 08:12:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: ef81dcdecb4d05c2f6d8d7fd8d77ae84 SHA-1: b4c423e31a8e88d9d2a119bba51dbb09277da8ab SHA-256: 8d4fbc6e7037a96db66f74a6320f11205cd84a087076c6129a5cc6809cdb4e45
156 Risk Score

Malware Insights

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

The sample was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous embedded URLs, many pointing to potentially compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The presence of external URI heuristics and the overall structure point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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 http://coffee33.ru/archive/file/varuza.pdf In PDF document text
    • http://canyonoaksmtg.com/~duckdi5/canyonoaksmtg.com/content/file/piwogaguzoduxoji.pdfIn PDF document text
    • https://grup-insaat.com/userfiles/file/daxuwigakul.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144a83761528---momixaleratu.pdfIn PDF document text
    • http://www.juniorcollege.cl/ckfinder/userfiles/files/pisazijotezuribewovoka.pdfIn PDF document text
    • https://www.indee-r.fr/wp-content/plugins/super-forms/uploads/php/files/ab64251c941398ee36ba86b63be26a61/99649958929.pdfIn PDF document text
    • http://nakamurasangyou.jp/app/webroot/uploads/files/xosen.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161304da24b333---66981732798.pdfIn PDF document text
    • http://myhomeinparis.com/userfiles/files/65569725091.pdfIn PDF document text
    • http://flooroverstock.com/admin/userfiles/file/51362141540.pdfIn PDF document text
    • https://pelletier-tp.fr/ckfinder/userfiles/files/65562754979.pdfIn PDF document text
    • https://rtaadmin.mrv-educationservices.com/content_file/files/20988343196.pdfIn PDF document text
    • http://mediaworld.pro/ckfinder/userfiles/files/lexafadoweto.pdfIn PDF document text
    • http://ttworld.hu/uploads/content_files/files/vexeseje.pdfIn PDF document text
    • http://wwstationery.com/files/file/memanixupomiwaxobumo.pdfIn PDF document text
    • https://nezrenweb.com/calisma2/files/uploads/nesirasuvixatos.pdfIn PDF document text
    • https://panificioilcavaliere.it/userfiles/files/59639026683.pdfIn PDF document text
    • http://kreativitaet-stadlhofer.at/global/images/userfiles/file/39298358601.pdfIn PDF document text
    • https://2b3la571ga-70p.com/contents/files/zotawidezixovusat.pdfIn PDF document text
    • http://clarksville.net/wysiwygfiles/file/widafikolunazedifid.pdfIn PDF document text
    • http://tentauto23.ru/ckfinder/userfiles/files/ribegebubadotujuzor.pdfIn PDF document text
    • http://bogaarchitetti.it/userfiles/files/budex.pdfIn PDF document text
    • http://luckdidea.com/ckfinder/images_store/files/vupiwudarabuj.pdfIn PDF document text
    • https://aparcaderoshaddaichile.cl/uploads/images/files/1863202809.pdfIn PDF document text
    • http://heilpraxis-pankow.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613c99b20be49---jajovexowamapetezi.pdfIn PDF document text
    • http://www.aportecnica.com/imagenes/editor/file/39685090124.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=leisure+suit+larry+reloaded+mod+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_off0000dca6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCA6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f4b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4B8 20244 bytes
SHA-256: 500eebd47015e0372ded49f5b2fdcc5ecb4a58652b3d407bd44f0709f5ca3c65
font_02_sfnt_off00012945.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12945 10712 bytes
SHA-256: b5582a82f1739f9d5613d8b639cf5b10e0b4a5ed5a5495865202ac710a52816f