Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f5f1e8dace33245…

MALICIOUS

PDF

81.2 KB Created: 2021-06-26 16:16:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: bfa7d12a088c1f907ffa37d711bc5cd5 SHA-1: 237d86be058d1416d391078ee7f4821498cff052 SHA-256: 4f5f1e8dace332454fb2d2d870979bd1e273a9254faff241787ea51a3870789b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous embedded URLs, 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 focus on directing traffic to external sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://infrive.ru/uplcv?utm_term=medical+suffix+osis PDF link annotation
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/160c03c8ce445b---wajujexu.pdfIn PDF document text
    • http://www.conectadoscomdeus.tv/arquivos/file/28017839771.pdfIn PDF document text
    • http://rogersdesignhouse.com/uploads/files/bepodesasesolefonix.pdfIn PDF document text
    • https://autoandtruckrepair.net/nbloom/fckuploads/file/2597268923.pdfIn PDF document text
    • http://lilit-realty.com/wp-content/plugins/super-forms/uploads/php/files/1v58vqis08e018v36ffljne6i1/39717661484.pdfIn PDF document text
    • https://www.bistro-e.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f6b845d454---45498787751.pdfIn PDF document text
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d4b8b5675e---koxubogunomi.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/rn367ojg214m4pbeue1dkta23n/60508815193.pdfIn PDF document text
    • https://motelandratecuci.ro/userfiles/file/6409183573.pdfIn PDF document text
    • http://zoncmswebsitebeheer.nl/files/editor/file/77820843716.pdfIn PDF document text
    • http://bayzones.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/taxate.pdfIn PDF document text
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/160ba7e19cbdc3---11843040720.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b013dda94ec---mozened.pdfIn PDF document text
    • https://naseeha.org/wp-content/plugins/super-forms/uploads/php/files/a3acbff79f9763d23e23b517df6aab93/34790844251.pdfIn PDF document text
    • http://opalsolar.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607a27033d791---80801149627.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/3cd5e4a298a2cb889b693a859a2198f5/bediv.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075a4f0c8967---wopize.pdfIn PDF document text
    • http://tevukasveza.lt/ckfinder/userfiles/files/muvurulaxuraxiwabijikid.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160ac21472e536---77281469857.pdfIn PDF document text
    • http://silesiacapital.eu/data/file/demokukaposugowolibinek.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607482e2f38b9---78580730111.pdfIn PDF document text
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/8311b754fb7d62326afbd29171e3af8f/wenopazejaf.pdfIn PDF document text
    • https://amenagementsoleil.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a71050bc651---73841178527.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/fjr390g9qffad66bbaa7o43f80/4816653855.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/16070ebb0afcf1---14043573335.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_off0000e15c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE15C 10364 bytes
SHA-256: 8c240a0287bae9de686905ad90bb8a60e0e0ff6bdc2be8cec579cfa90ee8bd86
font_01_sfnt_off0000f8e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8E7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000110f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110F9 15216 bytes
SHA-256: 53d3081eaa21c4c97552fbd42fadddf325f00e544a88a6700de2d443d5a52686