Malicious PDF — malware analysis report

Static analysis result for SHA-256 26255f5d50dfa417…

MALICIOUS

PDF

72.9 KB Created: 2021-03-15 01:48:47 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: cdb935598856d0f7ae4e41bb100861af SHA-1: c9a164e86430fbd780889faf1c78c694dc4c5e23 SHA-256: 26255f5d50dfa417ea321da193cb5d66fe13d5e1e4fb201be45ba603bf067b74
186 Risk Score

Malware Insights

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

This PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a large number of external links, many hosted on disposable domains, suggesting a link farm or SEO spam tactic. The document body, though heavily obfuscated, appears to be related to a 'blank spelling test template pdf', which is likely a lure to direct users to malicious websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://jacksth.ru/award?keyword=blank+spelling+test+template+pdf PDF link annotation
    • http://warupipujamoru.sportsontheweb.net/short_biography_of_mahatma_gandhi_in_english.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4378607/normal_60100f6086d87.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4475577/normal_603f3ad108047.pdfIn PDF document text
    • https://cdn.sqhk.co/nujusowidom/gdfggyl/poweramp_music_player_full_version_apk_free_download.pdfIn PDF document text
    • https://cdn.sqhk.co/goduwonon/1iciggc/12559245457.pdfIn PDF document text
    • https://cdn.sqhk.co/kawonidoza/jdjauwT/weather_nyc_celsius_10_day_forecast.pdfIn PDF document text
    • https://cdn.sqhk.co/nemanive/9IjghgZ/xemezepini.pdfIn PDF document text
    • https://cdn.sqhk.co/zebimapajod/ahcYggJ/how_to_be_a_certified_teacher_in_texas.pdfIn PDF document text
    • http://wupemokabate.scienceontheweb.net/cellulitis_guidelines_2020.pdfIn PDF document text
    • https://cdn.sqhk.co/momujolo/ia0iccV/zutatujuwox.pdfIn PDF document text
    • https://cdn.sqhk.co/lagolipumepi/fhhTDhe/81913061267.pdfIn PDF document text
    • https://cdn.sqhk.co/jozunufap/g9gbHqs/brentwood_council_housing_application_form.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470218/normal_602240bd52c26.pdfIn PDF document text
    • http://komaxinatobofe.medianewsonline.com/58358199387.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://danasavej.epizy.com/how_to_be_a_good_leader_at_work.pdfIn PDF document text
    • http://duxepivol.myartsonline.com/fearless_outro_song_1_hour.pdfIn PDF document text
    • http://rozazidugo.epizy.com/mckinsey_problem_solving_approach.pdfIn PDF document text
    • https://78e27e65-9996-4239-a63d-7a21722db537.filesusr.com/ugd/03f576_7a1d1c83226f456d9a801a1b5d4c6e09.pdf?index=trueIn PDF document text
    • https://d0275d90-c5b4-4c72-b581-d0e2b62fc6dd.filesusr.com/ugd/ee54da_c69f90647b504097a108c93e74f905e1.pdf?index=trueIn PDF document text
    • https://ed59cdd8-0d75-4634-8bb2-7afdb9da103e.filesusr.com/ugd/9cb112_9e2d41d3496d4aeb82169791dee4fe57.pdf?index=trueIn PDF document text
    • https://67bb8873-ca08-4da4-87c0-60a8072ebff6.filesusr.com/ugd/a838c0_58085aa37b08491ab91eb365b0d909cd.pdf?index=trueIn PDF document text
    • http://vutekumini.epizy.com/acceptance_of_resignation_letter_format.pdfIn PDF document text
    • https://6448a590-b571-4b71-a9e4-820b8531b153.filesusr.com/ugd/782be2_184c0a8a36f4479da60eec87f03b2e9f.pdf?index=trueIn PDF document text
    • http://poxizaxo.epizy.com/37304021741.pdfIn PDF document text
    • http://nibimasumexugi.rf.gd/html_css_templates_simple.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_off0000e16a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE16A 5376 bytes
SHA-256: 41f4a50a46b2503152fc0c6e9e82bb7fc80197b5ecc0c255167a777adf942ded
font_01_sfnt_off0000f3af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3AF 10020 bytes
SHA-256: a76a580ab16cd30f7b25de169ba6c8318e14ae8fee037632c7f76351ce0693d7