Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc320b9bd34811a0…

MALICIOUS

PDF

79.3 KB Created: 2021-09-12 18:07:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: c6cba1949ecc5e5a321c8b93a660ffbc SHA-1: d1fa30a711a02843249849a8f95930a9551e6860 SHA-256: dc320b9bd34811a041233a3762c9414471d498863cdf8b1273d58a841d5039bb
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting it functions as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of multiple compromised CMS upload links and disposable hosting further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://www.sandzthabapanel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161309adb4f5a3---72968336138.pdf In PDF document text
    • http://enewind.com/pliki/file/93511038144.pdfIn PDF document text
    • http://ackerviewguesthouse.com/userfiles/file/65541144920.pdfIn PDF document text
    • http://mkconline.com/landmark/ckfinder/userfiles/files/32567557221.pdfIn PDF document text
    • https://bartonsteel.com/tony/barton/ckfinder/userfiles/files/48268457124.pdfIn PDF document text
    • http://aodaibooking.com/FileData/ckfinder/files/20210906_F0D8109E07AE5F4A.pdfIn PDF document text
    • http://artstudiodesign.it/userfiles/files/sadugemebigitagonoz.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/09fc701d9f929711f28511483959e931/97459331798.pdfIn PDF document text
    • https://carmelocuritiba.com.br/ckfinder/userfiles/files/zifaj.pdfIn PDF document text
    • https://shotclock.ca/wp-content/plugins/super-forms/uploads/php/files/767e2c8acb747576ddd4f361c4e36ea7/77168705113.pdfIn PDF document text
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/16130cb5e4f31c---satubebetunow.pdfIn PDF document text
    • http://clubmaniacr.com/campannas/file/15561781309.pdfIn PDF document text
    • http://xiangzhuan.tw/upload/files/gareluwibe.pdfIn PDF document text
    • https://vnycc.com/userfiles/file/fasatexipesapopizefalo.pdfIn PDF document text
    • https://perfecthospitals.org/FCKeditor/file/pezifetejoxuv.pdfIn PDF document text
    • https://appvid.eus/userfiles/files/79495862902.pdfIn PDF document text
    • http://dorp.pl/userfiles/files/fotipojafor.pdfIn PDF document text
    • http://parilka.by/var/upload/file/patazetevetakidofix.pdfIn PDF document text
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/161395400efa54---88160795501.pdfIn PDF document text
    • https://atlantidegattico.it/file/furexot.pdfIn PDF document text
    • http://orchid-daikanyama.com/userfiles/file/zamaliwafurov.pdfIn PDF document text
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16131b04465e59---16411664245.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/3cc39a34655e5e3846b96de951b93cf6/tujisofaguvibisowotupujaz.pdfIn PDF document text
    • https://curewelldiabetes.com/userfiles/file/ludeguwuwilidume.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=bartleby+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_off0000cdbc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDBC 10588 bytes
SHA-256: 29354361392aba2967774325702cba631cebb4ccb4c4cdb555fa4cfb87106f63
font_01_sfnt_off0000e5c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5C8 19060 bytes
SHA-256: 9b65ac800c8d7b64deaf37c4a691642cb9b9ac44e6318d924bdfca7dc4a04fee
font_02_sfnt_off00011766.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11766 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1