Malicious PDF — malware analysis report

Static analysis result for SHA-256 812ab9957af38866…

MALICIOUS

PDF

77.3 KB Created: 2021-06-05 01:40:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 2c5197fc08cc513822bad6802d22181a SHA-1: b1f82e42d6da585275a57d21a4deb024a677f733 SHA-256: 812ab9957af38866e505e4c34472ebe38cd5c0d25b354240b33c0c8e8754fb0a
126 Risk Score

Malware Insights

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

The PDF contains heuristics indicating it is a link farm on disposable hosting, with a high ML score and ClamAV detection as Pdf.Phishing.Trojan. The embedded URL, https://ponafet.ru/123?utm_term=caaspp+ela+practice+test+answers, is likely the primary malicious destination. The document body, though heavily obfuscated, contains references to 'Caaspp ela practice test answers' and 'wkhtmltopdf', suggesting a lure to disguise malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://ponafet.ru/123?utm_term=caaspp+ela+practice+test+answers PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4459163/normal_6027ada86e980.pdfIn PDF document text
    • https://kirikunekev.weebly.com/uploads/1/3/4/7/134737840/3044075.pdfIn PDF document text
    • https://jivimukik.weebly.com/uploads/1/3/0/7/130775904/nesezetaxakabiparogu.pdfIn PDF document text
    • https://sijanobodebalu.weebly.com/uploads/1/3/4/6/134639398/9953805.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4476274/normal_6041950b5a820.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4374362/normal_60b7705b00c89.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4405208/normal_602f9e36945ed.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4379377/normal_6001bc293dd42.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4392659/normal_5fd64b961cc66.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4458827/normal_5fd03b017ae17.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387230/normal_601d5d98bfbfa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365567/normal_601490c63098b.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/646ef345-b8e7-4081-9e36-a7d0ed90090a/xidominuba.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/432654cc-ef14-4dc3-a28f-3b7c6ed71f12/pros_and_cons_of_transformational_leadership_theory.pdfIn PDF document text
    • http://wuwazilizos.pbworks.com/w/file/fetch/144630993/nukafe.pdfIn PDF document text
    • http://kapetipubi.pbworks.com/f/flexible_work_schedule_agreement_form.pdfIn PDF document text
    • http://tagexoba.pbworks.com/f/fluffy_slime_without_glue_borax_or_contact_solution.pdfIn PDF document text
    • http://wamotarirup.pbworks.com/w/file/fetch/144627045/gemotarezepoguxerorebema.pdfIn PDF document text
    • http://zupelapowi.pbworks.com/f/fiat_punto_service_manual_free_download.pdfIn PDF document text
    • http://jilawuxifi.pbworks.com/w/file/fetch/144547710/jipiguzesubatovukefidunos.pdfIn PDF document text
    • http://pigedigasexu.pbworks.com/w/file/fetch/144630150/free_leather_bag_patterns.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0b9dd8c5-d375-4c98-8933-40f8b4c58b35/zuretoruvu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d1b4aad9-da49-4310-a0a3-06cab2713925/smith_and_wesson_686-3_serial_number_lookup.pdfIn PDF document text
    • http://mevuteled.pbworks.com/w/file/fetch/144618282/dead_aid_moyo.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f24a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF24A 4924 bytes
SHA-256: d545efe1a66456b48ac756abfad1f10d4e994073c06cb27783595c154f142d69
font_01_sfnt_off00010327.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10327 10604 bytes
SHA-256: a589ea6e9d55e3de151604dbec2180e8d37e2e7d2b08d6c0bed86be770134895