Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9ce94e283fe50aa…

MALICIOUS

PDF

74.6 KB Created: 2021-09-19 17:57:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: f84377cd1256fe11f47b9a1fba0e44e6 SHA-1: 25bdb7b573900fabd606a902ce16584b8874a66d SHA-256: a9ce94e283fe50aabe73788eb739701fa5da271a60b115e97d5d120bffbd9e00
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS upload storage and disposable hosting. The document body is heavily obfuscated, preventing analysis of its specific content, but the presence of numerous external links strongly suggests an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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 https://foodthings.us/userfiles/file/tufeboxazaripusutuzu.pdf In PDF document text
    • https://karlschool.org/uploads/files/202109111553027324.pdfIn PDF document text
    • https://rajaketiga.com/contents/files/kagupo.pdfIn PDF document text
    • http://webcertain.ca/contentupload/fckeditorUploads/organization_/file/97769976947.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/9jifdl8l9ek0n5ut6q5hmn7a7s/bevufikuwaw.pdfIn PDF document text
    • http://sibleyestateplanning.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/99009859487.pdfIn PDF document text
    • https://binarbaidtrading.com/public_html/userfiles/file/14870295529.pdfIn PDF document text
    • http://www.barbazan-debat.fr/ckfinder/userfiles/files/kizojidepepomudamavigapi.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143c9bf009db---2538328229.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/43u8d2sota1mj4jp5m31nuneb7/24263648339.pdfIn PDF document text
    • https://insp.biz/img/file/6683357280.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/1613627aa93dd4---42362878926.pdfIn PDF document text
    • http://hdurmuslar.com/images_upload/files/bexetawiko.pdfIn PDF document text
    • https://www.vigo.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613c93f56ccfb---bedutiriguxefutokedowasar.pdfIn PDF document text
    • http://quantri.thaisonpalacehotel.com/upload/files/54173570348.pdfIn PDF document text
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135313672011---wanatovibako.pdfIn PDF document text
    • https://leise.ru/admin/ckfinder/userfiles/files/pemiwamuburaj.pdfIn PDF document text
    • https://rjpexport.com/files/pawopamizop.pdfIn PDF document text
    • https://thediamangroup.com/_images/files/lufarelima.pdfIn PDF document text
    • http://sevenseahotel.com/uploads/images/files/vofefinidadevibikuguzem.pdfIn PDF document text
    • http://kenshopvn.com/uploads/files/54404918496.pdfIn PDF document text
    • http://biswasi.com/userfiles/files/mafivij.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=android+studio+sqlite+selectPDF 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_off0000bed1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBED1 10428 bytes
SHA-256: f388797b5a1e9ae23d1c4d7a07cd89ec423e32b7092f9cefe0badf9f8bc83bb1
font_01_sfnt_off0000d65c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD65C 17976 bytes
SHA-256: 697f394cc2f337f041e62d7ecfc28df62bdd758ba2bae0be1319eefb1e9b860a
font_02_sfnt_off0001053d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1053D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1