Malicious PDF — malware analysis report

Static analysis result for SHA-256 843ad7fd3af4e503…

MALICIOUS

PDF

75.7 KB Created: 2021-06-10 21:38:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: 0bb9437d1e7936e093b4c83671811d29 SHA-1: 1bae289bf6bdc251056d22d655641b07380ab052 SHA-256: 843ad7fd3af4e5034a4b41f29b972a243d80faf4368953fb976d0c20e5a5311d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF document is identified as malicious by ML classifiers and ClamAV, detecting it as a phishing trojan. It contains numerous links pointing to compromised WordPress sites, likely serving as a link farm to distribute malicious content. The document body, though partially corrupted, suggests a lure related to educational materials, specifically a mathematics solution manual, to trick users into clicking the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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://crysiq.ru/uplcv?utm_term=solucionario+matematicas+aplicadas+a+las+ciencias+sociales+1+bachillerato+santillana PDF link annotation
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160ae9ffba5d74---wosugixeza.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ebe8975db9---bosesagakixisapotud.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607cbccf5f0bd---daliluwitijir.pdfIn PDF document text
    • https://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/a35b9b13ce70904a1ac34927cdeb439b/62892386581.pdfIn PDF document text
    • http://www.pianoszimmermann.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16088ba9c7d39b---bojibefitapawo.pdfIn PDF document text
    • https://bonpetsupply.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608917af5e478---dumezam.pdfIn PDF document text
    • https://benqmusicworkshop.com/fupload/file/51442283042.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608638b97a09d---93411600137.pdfIn PDF document text
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160803546c6c23---21096791482.pdfIn PDF document text
    • http://atek-ent.com/upload/file/surefasodafo.pdfIn PDF document text
    • https://ecobox.eng.br/wp-content/plugins/super-forms/uploads/php/files/cfi4s142j553vhepcp21cf0rvv/junewinifewegaratumuzipov.pdfIn PDF document text
    • http://fashioncenterpoint.com/wp-content/plugins/super-forms/uploads/php/files/d780789067b2cc9e9e5297b5d77b7cf5/81541388467.pdfIn PDF document text
    • http://www.ibadirect.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b87f1814864---verejatuliwizu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e891.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE891 5608 bytes
SHA-256: 69964e30b32abec371e0c2ec5463fefef08ce7d067b53b84fe2c5e5f9b56fc0d
font_01_sfnt_off0000fb74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB74 10880 bytes
SHA-256: a09e431e87a093b9c43c57f25676e90ba216e572100d1013ff54f1156be34149

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