Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4db5af6ee66e163…

MALICIOUS

PDF

86.4 KB Created: 2021-07-16 10:59:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: 3e278c5bca4df625e8441295a1c9e9d3 SHA-1: d1e3010be78bcff0fc398eaacb152db527957744 SHA-256: c4db5af6ee66e1634d909dbbb3658b7997e6c676f44ee5d659da447d30e0caca
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards exploitation or phishing attempts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://caratow.eu/userfiles/file/buguxeput.pdf In PDF document text
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/44820ef9ce1933d907a01963ca1f3af3/29798242979.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/160af28db53f63---9554460676.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/vikanakagonelajemu.pdfIn PDF document text
    • https://baconbites.com/wp-content/plugins/super-forms/uploads/php/files/klhmii6ro1itgcgqp4s5965kn5/30622947203.pdfIn PDF document text
    • http://guowangcable.com/d/files/84297112787.pdfIn PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16089265e8036a---ninebipodegim.pdfIn PDF document text
    • https://aimara-bg.com/userfiles/file/xobal.pdfIn PDF document text
    • http://mognational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609269974e1e5---59917681650.pdfIn PDF document text
    • http://ceraunavoltapizzeria.it/userfiles/files/tinoxedibowaperegote.pdfIn PDF document text
    • https://muzeumkonstancina.pl/attachments/file/10307520364.pdfIn PDF document text
    • http://lapenya.cat/imgjovesnaves/file/difefujenutegidapifafivi.pdfIn PDF document text
    • https://www.napariverinn.com/wp-content/plugins/super-forms/uploads/php/files/6bad02e3c59dfa320dfbace1e37dc9f7/jerivaf.pdfIn PDF document text
    • http://romengo.com/ckfinder/userfiles/files/robizozotewipetonok.pdfIn PDF document text
    • https://bellevuecommunityfoodbank.org/wp-content/plugins/super-forms/uploads/php/files/13a550beb94e38d2cd43ab11afca46d4/16626651779.pdfIn PDF document text
    • http://highlandlynxotic.com/clients/7/73/73cf6ae24f8ea70eb1cbac1dff6b0f9e/File/xixekewojapun.pdfIn PDF document text
    • https://ficsllc.com/wp-content/plugins/super-forms/uploads/php/files/4246vc1iueupdb2f106a46iuo7/nudererapaxejowukozaj.pdfIn PDF document text
    • http://rotarylaspalmas.org/documentos/file/80712113386.pdfIn PDF document text
    • https://journeypeople.cc/wp-content/plugins/super-forms/uploads/php/files/74f097a70d5f6e9c8ca223fac40c96ae/43025801088.pdfIn PDF document text
    • http://linker-apps.com/files/jupadiropemomuv.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/1606c94a11be42---74363300671.pdfIn PDF document text
    • https://uniontend.com/userfiles/files/37069141183.pdfIn PDF document text
    • http://mbcasc.net/imgs/file/52189235473.pdfIn PDF document text
    • https://thetitangroup.ca/wp-content/plugins/super-forms/uploads/php/files/164d53ae34795d2bdb4f88c067c27bb2/81255253054.pdfIn PDF document text
    • http://www.klpreschool.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d6b4f1df4e---natasezotasitulazavev.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=could+be+betterPDF 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_off0000ef7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF7F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010795.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10795 9984 bytes
SHA-256: 0f817120f60d76c3f99b40fa46b498d5eab50bf81ac3788dfbf96ef4b07cdb4d
font_02_sfnt_off00011dd4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DD4 17696 bytes
SHA-256: ad1fa4a1fa060e73614074c84112b6d2027d3fb8f1feb9756483869d7977a66f