Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f21668b40fc7d80…

MALICIOUS

PDF

87.1 KB Created: 2021-08-03 06:01:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 880e672dac068f52bdd494ff53d1c748 SHA-1: 3012ff55c6a739443aa2746c3a27fa0f855591c1 SHA-256: 4f21668b40fc7d80e3ce2ae25dfd64a9dffdd826412af9be920dc8543a681d31
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the structure and URL findings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/6b0ac79f760d0aedd103b8ac2a468e27/dogebikosenanub.pdf In PDF document text
    • https://svetpoznaniyaonline.ru/wp-content/plugins/super-forms/uploads/php/files/548848ad86f6cd60fb11564e2c645327/8054014151.pdfIn PDF document text
    • https://www.helmmsp.ca/wp-content/plugins/super-forms/uploads/php/files/94e91b9c4e641a67d765dd120b492c08/mezitanurifopaloti.pdfIn PDF document text
    • http://cambresisemploi.fr/ckfinder/userfiles/files/80639928150.pdfIn PDF document text
    • https://www.azembay.com/wp-content/plugins/super-forms/uploads/php/files/g9ll06d1fq49uil5j78d295b9a/xabariruzifinoxaxumiwe.pdfIn PDF document text
    • http://ssaisarang.com/ckfinder/userfiles/files/80048768537.pdfIn PDF document text
    • https://journeypeople.cc/wp-content/plugins/super-forms/uploads/php/files/fa70e608eaf99df118a262c6703f71c7/81092346545.pdfIn PDF document text
    • http://bioident.pl/photos_fck/file/17196995212.pdfIn PDF document text
    • http://cungcapluonech.com/upload/files/25605419914.pdfIn PDF document text
    • https://ekransamara.ru/files/sakudekelodinagotazope.pdfIn PDF document text
    • http://bearings-home.com/userfiles/file/38582827773.pdfIn PDF document text
    • https://www.lightingsolutionsal.com/wp-content/plugins/super-forms/uploads/php/files/3615cb0258225ac13e082da2fbd84ce5/puteliwoja.pdfIn PDF document text
    • https://www.kadeavenue.com/wp-content/plugins/super-forms/uploads/php/files/a3c7384549a1609bdb7c82928f43cc50/devaxowuporogoko.pdfIn PDF document text
    • https://abhimaninteriors.com/ckfinder/userfiles/files/19511673403.pdfIn PDF document text
    • http://luluscafeonline.com/uploads/files/zavoxon.pdfIn PDF document text
    • https://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/6pk5u6qelafngef8kl69f8a5hi/vetidus.pdfIn PDF document text
    • https://grup-insaat.com/userfiles/file/88237021016.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a03bf6aff10---76066540106.pdfIn PDF document text
    • http://iowatriallawyer.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/27536389634.pdfIn PDF document text
    • http://francisfamilyreunion.net/clients/870293/File/vakozetuxafetitapiwetesa.pdfIn PDF document text
    • http://www.cheapmotorcycleinsurancepa.com/wp-content/plugins/super-forms/uploads/php/files/dvedn2isud6is7d7sch14shro1/50863988997.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ed8ae3682ab---43537742250.pdfIn PDF document text
    • http://j1medical.com/uploaded/file/17769600249.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/f35dbe0c2ea248fb0326dae16e514803/rewafimomovofowitaneza.pdfIn PDF document text
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/cf92d4177997a3f1eb301882013361d9/82136344582.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=how+to+pass+dmv+written+test+2019+californiaPDF link annotation
    • https://www.posluh.hr/ckfinder/userfiles/files/lavejobalejizopuzuxuxix.pdfIn PDF document text
    • 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_off0000edd0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDD0 11384 bytes
SHA-256: 4eca2aecfb86dbe934b224cee28ccf90375d2ed475f8381fc2e01cf54a502cbf
font_01_sfnt_off000108bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108BB 17328 bytes
SHA-256: 51ef7366b7dec3df9b23adc73e468ed9ae123ad5402cf134c8dcec5c1f4463f2
font_02_sfnt_off00013627.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13627 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1