Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef39af14eea5c1ce…

MALICIOUS

PDF

80.1 KB Created: 2021-05-17 08:59:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 31b555b8a9d8e2c88f8a982047440dde SHA-1: b6db5407f86b31aeb4b51e04e451a036879a3c01 SHA-256: ef39af14eea5c1ced6b0b9907e864feef72cd61e3ed3b7b9f830cc24c2f2f1ac
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, with a primary suspicious URL pointing to 'xajibur.ru'. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create malicious PDFs. The presence of multiple external URIs and the overall structure indicate an attempt to redirect the user to a malicious site, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 5

  • 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 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://xajibur.ru/strik?utm_term=k9+mail+alternative+reddit PDF link annotation
    • https://cdn.sqhk.co/bijukipuj/jiiajji/75272052889.pdfIn PDF document text
    • https://cdn.sqhk.co/kitujesijak/g6gjjff/gebefarumusoranuf.pdfIn PDF document text
    • https://cdn.sqhk.co/kepebeso/0hfRIhi/rechargeable_hand_warmers.pdfIn PDF document text
    • https://cdn.sqhk.co/mewowoji/Gihyic5/download_game_hungry_shark_heroes.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4368475/normal_5fca6f2ef019c.pdfIn PDF document text
    • http://vesajob.getenjoyment.net/pathogenesis_of_diabetic_retinopathy.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391599/normal_605aabad4ff80.pdfIn PDF document text
    • http://vujenixuwo.mypressonline.com/nodamafepoboga.pdfIn PDF document text
    • https://cdn.sqhk.co/jirowolad/zgcbhaw/house_paint_colors_images_outside.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4495043/normal_5fc7ef3b8a083.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://gibidapasajug.atwebpages.com/bronze_casting_process.pdfIn PDF document text
    • https://s3.amazonaws.com/pubopelej/11755941226.pdfIn PDF document text
    • http://viwuwijagabote.myartsonline.com/thin_aerofoil_theory.pdfIn PDF document text
    • http://kirigawegugava.epizy.com/2020_acc_basketball_tournament_bracket.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b50a3226-5772-4a8c-9c30-a54eb3b29a4f/ti-30x_iis_change_battery.pdfIn PDF document text
    • https://s3.amazonaws.com/falejogajir/4402532065.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/22d50dfe-82f4-4238-be84-64446a88537b/kung_fu_panda_4_full_movie_free_online.pdfIn PDF document text
    • http://bisowukaka.rf.gd/analog_electronics_objective_questions_and_answers.pdfIn PDF document text
    • http://xokutamewa.rf.gd/lanujejutijabiduwu.pdfIn PDF document text
    • https://s3.amazonaws.com/zulezov/hd_movies_telugu_2016.pdfIn PDF document text
    • http://vedebimefawimad.rf.gd/49238914883.pdfIn PDF document text
    • https://s3.amazonaws.com/bejenosugede/minecraft_fireworks_crafting_guide.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0a2040e9-9d43-435a-baab-161092efd944/78355413373.pdfIn PDF document text
    • http://xuvuzonixo.onlinewebshop.net/agile_software_development_principles_patterns_practices.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ee3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE3E 4656 bytes
SHA-256: 13db2efbed695398e64a9c120e4ba6a83f6eac19f5eccfc8ae8a72e914a6e402
font_01_sfnt_off0000fdeb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDEB 11384 bytes
SHA-256: ac9606aa565c5895eac2a754dabad52f1dac21f7de6577585def2dd6a8ccb099
font_02_sfnt_off000124b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124B3 4324 bytes
SHA-256: 4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3