Malicious PDF — malware analysis report

Static analysis result for SHA-256 c3f7e1bdbf4014f1…

MALICIOUS

PDF

86.6 KB Created: 2021-08-08 08:36:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 2c8dde31f3d57ec0a79505b2aa5a17bf SHA-1: 49800ae32f0326b3a6bdcba9fb9b20a02ab4bde1 SHA-256: c3f7e1bdbf4014f17a055ee70193c1aa51933f3f6093399d91fcf5854f402a0e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous external links, many of which point to compromised WordPress sites, indicating a link farm designed to distribute traffic to potentially malicious destinations. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery. No scripts were extracted, and the document body was unreadable, so the rationale is based on the link farm behavior and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b050307b005---76231867136.pdf In PDF document text
    • http://kehlux.lu/userfiles/files/damupexa.pdfIn PDF document text
    • http://elyriahigh1974.org/clients/0/05/052ab20d644b737728595af1a47b4450/File/nuburorenetujipatisevak.pdfIn PDF document text
    • https://signaturetowerpune.com/wp-content/plugins/super-forms/uploads/php/files/u6pjaqijunj8bd3foh8010hj97/60074988118.pdfIn PDF document text
    • https://benjamindreyer.com/wp-content/plugins/super-forms/uploads/php/files/9b970037737ac049d37adf65fafa8a27/raxabazo.pdfIn PDF document text
    • http://al-farh-iq.com/upload/userfiles/file/36296393497.pdfIn PDF document text
    • http://qhzs88.com/admin/fckeditor_upfiles/file/2021072004064380554.pdfIn PDF document text
    • http://mayamalay.com/clients/874202/File/lonutizisuxufogifuli.pdfIn PDF document text
    • http://msiutilities.biz/documents/36513538648.pdfIn PDF document text
    • https://discoverapartmentsforrent.com/wp-content/plugins/super-forms/uploads/php/files/460d7e65369735bd86a22ac4d323d96d/10315960704.pdfIn PDF document text
    • https://alves.bg/ckfinder/userfiles/files/77930123101.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1609d045475135---37716093589.pdfIn PDF document text
    • http://vdgairconditioning.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160934d1ee427b---40120423478.pdfIn PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607c631db8995---90391465204.pdfIn PDF document text
    • https://local-atlas.ru/userfiles/files/tazow.pdfIn PDF document text
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160743f3c8c421---devuluwevimin.pdfIn PDF document text
    • https://mailing.crpm.ch/ck/ckfinder/userfiles/files/47861220314.pdfIn PDF document text
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/35ebc498728cbca4c93eb44c2082fec5/junujedizobinanexeketofur.pdfIn PDF document text
    • http://ylpcl.com/ckfinder/userfiles/files/rutonusuvipuvekuvaza.pdfIn PDF document text
    • http://nhasachconggiao.com/luutru/files/rokunupufosozekomo.pdfIn PDF document text
    • https://burstallconrad.com/editor_files/file/50599818574.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=canzoni+di+natale+per+bambini+asilo+nidoPDF 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_off0000ed50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED50 10784 bytes
SHA-256: e37b1e29258f9489362d2ed9d283b49a2ec3e9777a7e6d49e762fc8e668c3df9
font_01_sfnt_off000105f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105F5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011e07.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E07 17780 bytes
SHA-256: 45e3f85dc9e4c0d06c96fe34f249a8e85ab15f825ebbd47e660fe0544bd7a711