Malicious PDF — malware analysis report

Static analysis result for SHA-256 d78d4476b2f4b394…

MALICIOUS

PDF

88.7 KB Created: 2021-07-25 13:33:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: e8c041fa417b4b19de6eb0e5d6179d57 SHA-1: 0aa70dbc874bd296f2d5d2a5f10e2c0ef7d9578e SHA-256: d78d4476b2f4b3944f0eb83206d3d06ac20ba59f0237a136702ac5d986a33839
204 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1539 Steal or Harvest Credentials

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate the presence of a link farm on compromised WordPress uploads and a lure for MFA or one-time code harvesting. The document body, though heavily obfuscated, contains references to wkhtmltopdf, suggesting it was generated by a tool. The embedded URLs, particularly the one pointing to a compromised WordPress upload, are strong indicators of a phishing or credential harvesting attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • MFA / one-time-code harvesting lure high SE_MFA_LURE
    Document asks for a one-time code, authenticator approval, or MFA confirmation — consistent with credential phishing kits that steal session tokens or abuse multi-factor authentication
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/16077c9fce7f96---369563235.pdf In PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/160cc6250ac698---91462652729.pdfIn PDF document text
    • https://djennebeads.com/nbloom/fckuploads/file/3550960146.pdfIn PDF document text
    • http://bakkervoorwinde.nl/app/webroot/files/ckeditor_files/files/80939813078.pdfIn PDF document text
    • https://outsourcedbackoffice.co.uk/wp-content/plugins/super-forms/uploads/php/files/e816d31b551d5a96098069b0f5ef42ee/703058755.pdfIn PDF document text
    • http://hwayinn.com/image/files/20210622_185747.pdfIn PDF document text
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/aed08ae6425c5c631ae83366d343768f/xarixe.pdfIn PDF document text
    • https://audreyheselmans.com/_files/file/xefumobelo.pdfIn PDF document text
    • https://xn--interpeas-r6a.es/upload/files/40317744285.pdfIn PDF document text
    • http://andrelandberg.com/userfiles/file/12091161506.pdfIn PDF document text
    • http://abbuffalowings.com/uploads/files/nabududagobagewerapaga.pdfIn PDF document text
    • http://globalquestconsulting.com/userfiles/files/finufelunemutemeb.pdfIn PDF document text
    • https://asset-books.com/userfiles/file/3004377601.pdfIn PDF document text
    • https://g55net.com/webpagebuilder/ckfinder/userfiles/files/sadalanivixakoxobenaw.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a03ddcc5af---riwezunagijirowerejosiba.pdfIn PDF document text
    • https://voolabs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f66bc8b0a5---19815345645.pdfIn PDF document text
    • https://lawpropertyconsultants.co.uk/wp-content/plugins/super-forms/uploads/php/files/sfkbh74huj1hsoglb5gmrnm78q/padapes.pdfIn PDF document text
    • https://arrayamed.com/userfiles/file/lobejulemeru.pdfIn PDF document text
    • https://gulertrafik.com/wp-content/plugins/super-forms/uploads/php/files/945um76lur0kkk5nmnfqu8avas/3356468831.pdfIn PDF document text
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d9eb74e1835---towogim.pdfIn PDF document text
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086cb425de9a---gaxudip.pdfIn PDF document text
    • http://ecohouse-lab.com/userfiles/file/92129409063.pdfIn PDF document text
    • https://alatheir.com/atheirwsfiles/file/vivipewikawib.pdfIn PDF document text
    • http://hz-karavany.cz/ckfinder/userfiles/files/54494813332.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/77421967701.pdfIn PDF document text
    • https://franchiseharbor.com/files/files/46834911747.pdfIn PDF document text
    • http://portsreunion2021.com/clients/b/b1/b1889431de095b9710a1303a3c619afc/File/90946462714.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=sharp+tv+manual+downloadPDF 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_off0000f641.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF641 17328 bytes
SHA-256: 6d104c42a79c7430d1a55e8ab9c62adaa8a7e538372a59081aa2c8329ec1f7f5
font_01_sfnt_off000123f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123F5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013c0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C0C 10592 bytes
SHA-256: ff111bc1e33cdec3248117462ad311da02d2198a1808725b496120f3f1851c11

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