Malicious PDF — malware analysis report

Static analysis result for SHA-256 55505c24267e33bc…

MALICIOUS

PDF

75.8 KB Created: 2021-04-06 22:35:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-24
MD5: ad7fc4e65603c13e776a0361de576a62 SHA-1: 52c8a3c92d937c426cbe899a3ec810ee44f82620 SHA-256: 55505c24267e33bcb50c7121400cce0b5d929be1f9941c30d49fcba0d67a343a
166 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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=pdf+to+autocad+drawing+converter+free+software+download PDF link annotation
    • http://wimawukit.iblogger.org/bolobalinunomufezesina.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4497369/normal_5fd1636d4692e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4484399/normal_605283599c03b.pdfIn PDF document text
    • http://nezowawamelepi.iblogger.org/bpsc_complete_syllabus_2020.pdfIn PDF document text
    • http://frukt.fun/dobuvozefufuden64t4t.pdfIn PDF document text
    • http://masalev.ru/jozuxiwunisezitutikizitokabmar.pdfIn PDF document text
    • http://musc-media.xyz/2166308486l9z8a.pdfIn PDF document text
    • http://pixell.store/sheridan_king_single_bed_sheetsm6ekz.pdfIn PDF document text
    • http://interplast.ru/17770673047r3l1g.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4412382/normal_6066a70dede7e.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://3745348a-78a0-42d7-8ff4-af2b45bf5faf.filesusr.com/ugd/02631b_75d8e50520794c1b8b975f28354dbc8b.pdf?index=trueIn PDF document text
    • http://varaxijolos.rf.gd/71447774204.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/583fd23f-58df-4803-b6fe-231c50eb3d62/alaska_driving_test_requirements.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5c198408-6c2d-4989-8b1d-adf4e3d3d45b/new_king_james_version_bible_price.pdfIn PDF document text
    • https://fe2b84af-b373-48e0-a714-f820169e3fe9.filesusr.com/ugd/ed1d2e_c9e5d39ff8fe4512991ea750ef3d9c16.pdf?index=trueIn PDF document text
    • https://c7fb3737-a2fb-4e06-b71d-f78b648bb0a4.filesusr.com/ugd/a9248e_b06a4abce9b44aee91f7793832026bb0.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/66285c0e-68fa-4f67-9001-211e2c2127e4/dd_books_for_beginners.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c72829cf-249f-4d51-bdb4-622c932e34e7/excelsior_college_nursing_login.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4514fe6a-5481-4f4b-b18c-96f387f47b60/vavegenedubumumupomenotus.pdfIn PDF document text
    • http://pewulalabes.epizy.com/berkheimer_estimated_tax_forms_2018.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/215f0134-f154-4f2a-9730-7e493754d537/vivoxufozafajiro.pdfIn PDF document text
    • https://6a421494-2577-4416-904f-e17348f56b63.filesusr.com/ugd/85e76a_84f4f46ff60c4f1f8735afd7a01ec971.pdf?index=trueIn 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_off0000eb84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB84 5344 bytes
SHA-256: c49875a18083cee76e28843ee7a5c5d93db6eaff0a66e9b663108bcc8fdae004
font_01_sfnt_off0000fddf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDDF 10296 bytes
SHA-256: cdb577f054a2d7573054578bff8acbf5e01d0a0f3299fad9608a7390e65453b4