Malicious PDF — malware analysis report

Static analysis result for SHA-256 82840813a1fed65e…

MALICIOUS

PDF

79.7 KB Created: 2021-06-10 18:57:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-23
MD5: 753d72f739085837369647337b615a42 SHA-1: 126fb08ee9f861dcbd2ab046ac2a3b3a9e7fbfa7 SHA-256: 82840813a1fed65eeccfeaa47b4bcb2181689cdb48bc799dcc0373188e9edf6d
156 Risk Score

Malware Insights

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

This PDF document is classified as malicious by ML models and ClamAV, indicating a phishing or trojan threat. It contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The document body, though heavily obfuscated, appears to be a lure for 'Maths textbook 9th standard', likely to trick users into clicking the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://cructi.ru/uplcv?utm_term=maths+textbook+9th+standard PDF link annotation
    • https://www.vigo.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a4ee31289d0---resajejexa.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/n0p4vfjaefi6vejd67mlg1kttg/ruzed.pdfIn PDF document text
    • https://aliencosmicexpo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160717bb65cabc---75737631198.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/6g72jemooujohou043bfjidgqn/5613436855.pdfIn PDF document text
    • https://legacyltg.com/wp-content/plugins/super-forms/uploads/php/files/f240ac733d2cc297861d866cca27c30a/nekivisugexataxutavuzexe.pdfIn PDF document text
    • https://www.endthestigmacounselling.com/wp-content/plugins/super-forms/uploads/php/files/cs2hai02mnohge6ab9kqrnl4du/24497748519.pdfIn PDF document text
    • https://fellowpeo.com/wp-content/plugins/super-forms/uploads/php/files/ffbe3c611ce144ad8873a4d747ba8de1/mutonedaxagutukek.pdfIn PDF document text
    • http://artospace.com/pics/file/55416942879.pdfIn PDF document text
    • http://aylincinarli.com/fckfiles/file/kinad.pdfIn PDF document text
    • https://xn--80aaaglcftt5alesfkk7f.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/6b63f5eb04f5db32c741b67dd7b8fb30/73061571709.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a9c618bb944---99641194867.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16075b481126bf---nalimamukedunugofu.pdfIn PDF document text
    • http://beckydavidsonhomes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0a32ce42f0---53593602906.pdfIn PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16073e81b168d8---kogutefijixixele.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://fedorahosted.org/lohitIn 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e10d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE10D 5312 bytes
SHA-256: ff041865b5a6018c5725f2bc6b4bbef9a933d7df271eea00739a4c9d006cce9b
font_01_sfnt_off0000f318.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF318 11032 bytes
SHA-256: a45b10b49f5d142dacde90c928e0350eeb537b3f4089bf61610e9763487d346e
font_02_sfnt_off000118ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118ED 7436 bytes
SHA-256: 4f80657cffd1ad265a12292963a162195e35551464fd485a47b6c87b8f24a1cc