Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf33f252b732af63…

MALICIOUS

PDF

79.8 KB Created: 2021-09-05 11:35:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a3a95d96d3e4d6e6c9a77a0648c4c4b2 SHA-1: 9b6ef21229b2d77ba2fcf61caada9dd3bee1aa09 SHA-256: cf33f252b732af634ce113182d20164ed1bf71313bd9cad3b307529f86d041a8
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of multiple distinct hosts and the use of formcraft plugin uploads suggest a coordinated effort to host malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16102d3c03b339---56631832428.pdf In PDF document text
    • https://atlanthealth.com/wp-content/plugins/super-forms/uploads/php/files/8ac593db7bf3a684a04994a72bf94b5f/72583605162.pdfIn PDF document text
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16070f8aeedcb8---26377622034.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16107255229ef7---50919674997.pdfIn PDF document text
    • http://podlahypilat.cz/admin/file/pukivilediperososiren.pdfIn PDF document text
    • https://tecnicadovolante.com/images/file/64787487935.pdfIn PDF document text
    • http://lorichphoto.com/pictures/file/61232820822.pdfIn PDF document text
    • http://vanxuantravel.com/upload/files/vituseniwix.pdfIn PDF document text
    • https://delaneyllc.com/ckfinder/userfiles/files/befevuved.pdfIn PDF document text
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/37016ee7e8378f67eca2d028ff54b453/saxobonisoxebil.pdfIn PDF document text
    • https://alkhairi.co.uk/wp-content/plugins/super-forms/uploads/php/files/8bacda51041410242a9db2c1512ef7b9/57837222018.pdfIn PDF document text
    • https://doitsolutions.co/wp-content/plugins/super-forms/uploads/php/files/7d5b9d7e6c5bb485c456ed4f8c6a650d/gemokifobojoruvubadogese.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a419d781e9f---fovixisim.pdfIn PDF document text
    • http://nuovojob.com/userfiles/files/82884881323.pdfIn PDF document text
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609f39875ed7a---35846542546.pdfIn PDF document text
    • https://www.ltgpartners.com/wp-content/plugins/super-forms/uploads/php/files/29ae4469d5b42ed5cb3a5c8464dfd079/rabanazedasoteguwanop.pdfIn PDF document text
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095566f5c5cb---wugulomikawapovonafo.pdfIn PDF document text
    • http://zulassung4you.de/bilder/file/vubepedozoxisemiwona.pdfIn PDF document text
    • http://bielwod.com/userfiles/file/silow.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/d3a338e024dc4f1ad9890101d075d4b3/parilimixus.pdfIn PDF document text
    • http://niezapominajkowo.eu/userfiles/file/zosisufejenojasapuki.pdfIn PDF document text
    • https://hospvetcentral.pt/site/upload/file/20651007458.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bc71e0bc633---11403116525.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16080128c1e845---66976028883.pdfIn PDF document text
    • http://ekvatorbl.com/userfiles/file/medezubetoxaxugiku.pdfIn PDF document text
    • https://unaizahic.com/Files/files/30902130420.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=sheet+metal+handbook+pdfPDF 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_off0000d5a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5A8 10712 bytes
SHA-256: 1ce3e22e281de8ed73df3f0a9b213452f64529aa4a822fa496ee312c753ce008
font_01_sfnt_off0000edd7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDD7 16868 bytes
SHA-256: e822b2a6d5f820756c68f4dc47b2206f5248d0c9b3b590c5bbdd15f126969afe
font_02_sfnt_off00011935.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11935 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1