Malicious PDF — malware analysis report

Static analysis result for SHA-256 851abb69fbbb3c9b…

MALICIOUS

PDF

78.8 KB Created: 2021-03-29 13:54:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 3478dc4454684bb08c1167d42d0e0942 SHA-1: c49722f309c7be98950641bf3d53e583741378e7 SHA-256: 851abb69fbbb3c9ba2ba80c4320fc5747b3e72e7067bfffc6f914d1af5feb218
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, with one prominent URL leading to a disposable hosting domain and a keyword suggesting a lure for educational content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded links are characteristic of a malicious document designed to redirect users to harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://lozipotod.ru/wix?keyword=paso+a+paso+1+capitulo+8+workbook+answers PDF link annotation
    • https://cdn.sqhk.co/retagigimusa/YQgigKE/ludo_game_download_apkpure.pdfIn PDF document text
    • https://cdn.sqhk.co/jarebomu/9jddZqB/bharti_airtel_annual_report_2016.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4448976/normal_5fc6f41c8529b.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4416935/normal_5ff13d045dd6d.pdfIn PDF document text
    • http://raisinsapp.club/640323233184ajl2.pdfIn PDF document text
    • http://helplnstagramcontact5087423.com/mitanuvajitevovejixufgixv6.pdfIn PDF document text
    • https://cdn.sqhk.co/pajazidif/jdMig3i/81831684983.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4404753/normal_5feb48d82003c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4447265/normal_6013222070b2f.pdfIn PDF document text
    • http://wdd13.ru/usmle_step_1_2021b7mxh.pdfIn PDF document text
    • http://digitalmicroteter.xyz/nawufipimemudufejawqe7ym.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/sedowedi/jubekepijobarora.pdfIn PDF document text
    • https://s3.amazonaws.com/vebisop/noliwiji.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3f352bf5-a6aa-4e19-a08f-6496b4dabdec/49525377445.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5859e8da-17b3-4438-aa45-a9ff4ce3f8cf/bob_revolution_pro_2016.pdfIn PDF document text
    • https://s3.amazonaws.com/mexijegedakol/payroll_processing_checklist_template_excel.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5274d3d2-387b-45b1-a500-d5abe070a1e6/shakespeare_plays_tempest_characters.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6a1b1ad9-39ce-4c19-933d-8a9aa708dac8/what_is_the_best_way_to_analyse_qualitative_data.pdfIn PDF document text
    • https://s3.amazonaws.com/liwafo/integral_secx_tanx_3_sec_x5.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/807d3650-de1d-45a2-bce4-7ed2f9e1fd9f/sigirozuwixaxewanen.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/41fc3797-88b9-4cdf-a79e-3d7d417c0593/pojefilagebuwow.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bf894647-de66-4dde-9b78-ec70a38b7965/88278368133.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_off0000df03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF03 6472 bytes
SHA-256: 4f77fbdcea22258105ec0b004104816f3f553cf1410baf17e4b3ec9fe945141c
font_01_sfnt_off0000f557.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF557 5468 bytes
SHA-256: 31403a05021363697027dbb1f014a74f9cced65867a528bbe3e6995fce73cbb7
font_02_sfnt_off00010817.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10817 10368 bytes
SHA-256: ee8052f82305169bd402287c5a0cfdf427c505346405c5ba4f952fea1b47863b