Malicious PDF — malware analysis report

Static analysis result for SHA-256 c0ae23c8553117ee…

MALICIOUS

PDF

91.7 KB Created: 2021-03-31 07:45:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: 8d61990dbffb2b936c3d8483fb3177d7 SHA-1: 235b8dcefc3497f1ae0853b3de64983e20660f46 SHA-256: c0ae23c8553117ee33a21969da8ba2672f64b05d203fa519877bd635c7b8aaf3
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains a link farm with numerous external URLs, including one pointing to 'pelibifir.ru', suggesting it's used for phishing or distributing further malware. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and 'excel formulas', likely serving as a lure to encourage users to click on the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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
  • 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://pelibifir.ru/award?keyword=basic+knowledge+of+excel+formulas+pdf PDF link annotation
    • https://cdn.sqhk.co/vixivizal/jbbhdyL/russian_car_simulator_apk_mod.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4425009/normal_6040a9306be18.pdfIn PDF document text
    • https://cdn.sqhk.co/lamiwifa/4EjhalG/zombie_age_1_mod_apk_download.pdfIn PDF document text
    • https://cdn.sqhk.co/wujakegu/ggGhgdS/new_ringtone_2019_download_tamil_mp3.pdfIn PDF document text
    • https://cdn.sqhk.co/simixejazir/djijgdf/world_conqueror_1945_mod_apk_free_download_ios.pdfIn PDF document text
    • https://cdn.sqhk.co/zovitamojim/jcNm0jc/89297240515.pdfIn PDF document text
    • https://vasalidut.weebly.com/uploads/1/3/0/9/130969475/5884504.pdfIn PDF document text
    • https://cdn.sqhk.co/wogefosa/gfmgghq/beyblade_burst_wall_stickers.pdfIn PDF document text
    • https://cdn.sqhk.co/mapexuze/hcfM0jb/xogifatosutaxo.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4486365/normal_5fe7c02c20dfb.pdfIn PDF document text
    • https://cdn.sqhk.co/kusamika/hcblijc/metal_gear_solid_3_ringtone_codec.pdfIn PDF document text
    • https://cdn.sqhk.co/kerikone/P3P7ig0/win_10_theme_for_computer_launcher_2020_apk.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4384634/normal_5fcd720dab46e.pdfIn PDF document text
    • https://giruwikepu.weebly.com/uploads/1/3/4/4/134464081/panagepetezogejot.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4458635/normal_6034dd5195eeb.pdfIn PDF document text
    • https://guzepebizosi.weebly.com/uploads/1/3/4/8/134880367/sigazijavi-sajimutil-nurajo.pdfIn PDF document text
    • https://cdn.sqhk.co/jidelugob/gifhejf/cute_animal_pictures_desktop_backgrounds.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://1a2149e7-ca7f-4e7c-a584-0e483de6f3af.filesusr.com/ugd/9219f8_802f0a9e3297495d8d4e7940a41c8017.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/mejobu/community_service_hours_verification_letter_template.pdfIn PDF document text
    • https://042e50b4-45d0-4577-915a-c14d43ab21ad.filesusr.com/ugd/18f527_e599088178684dccafaeb40bede04822.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/vabedafozo/cash_book_and_ledger_software_free.pdfIn PDF document text
    • https://s3.amazonaws.com/gonafoziguwewe/98287669962.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_off000125ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125CA 5748 bytes
SHA-256: c6d4d44e9de5e963b75c281673d3f7752433d0677f34e2fb4810274e39c22910
font_01_sfnt_off0001396c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1396C 11708 bytes
SHA-256: 31066dcf06362580f04e6207c5e90933b315262154ae2adb7aada2f47822866d