Malicious PDF — malware analysis report

Static analysis result for SHA-256 857f578ec8c19d6e…

MALICIOUS

PDF

75.6 KB Created: 2021-05-16 02:28:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 99428728528063f6cc19e42300ba1c4b SHA-1: 7ef6e842a9d904139d956c7c17e0d3d5ecd9d9f4 SHA-256: 857f578ec8c19d6e3def0818254533ffa7f6b018991c3183a1344e4a1bb5208a
186 Risk Score
Tags
free-cdn-ebook-manual-lure

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO manipulation tactic. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://vilenefex.ru/strik?utm_term=yard+machines+by+mtd+snowblower PDF link annotation
    • http://dividogozurunuz.iblogger.org/fundamental_of_accounting_principles_23rd_edition.pdfIn PDF document text
    • https://cdn.sqhk.co/gobisofokox/eidoggK/secure_folder_download.pdfIn PDF document text
    • https://cdn.sqhk.co/nosimasiv/JVhhZjd/rolling_stones_tongue_shirt_black.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4503584/normal_600d516d72a3b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4488837/normal_6054228c83888.pdfIn PDF document text
    • https://wawotisusuwo.weebly.com/uploads/1/3/2/7/132741293/xazopapegefuburorada.pdfIn PDF document text
    • https://cdn.sqhk.co/xekemini/nqhd0iP/77155000961.pdfIn PDF document text
    • https://cdn.sqhk.co/donaxewon/jgmBGge/break_the_prison_mod_apk_latest_version.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4382965/normal_60067ba7696b8.pdfIn PDF document text
    • https://cdn.sqhk.co/nimuxugemu/0fegiVe/xuxusa.pdfIn PDF document text
    • http://vevaxogejaz.scienceontheweb.net/fawiravogade.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4374366/normal_5ffcc5ccdb123.pdfIn PDF document text
    • https://xufetujada.weebly.com/uploads/1/3/4/7/134745175/4c182.pdfIn PDF document text
    • http://retamos.mygamesonline.org/pdf_alternator_manual.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
    • https://s3.amazonaws.com/bisazabe/hubspot_agency_partner_certification_exam_answers.pdfIn PDF document text
    • https://s3.amazonaws.com/fekaduvopigab/how_do_you_pray_using_the_acronym_act.pdfIn PDF document text
    • https://s3.amazonaws.com/tajimipojimo/where_to_buy_gravity_falls_journal_3_special_edition.pdfIn PDF document text
    • https://s3.amazonaws.com/gelawiweza/internal_combustion_engine_second_industrial_revolution.pdfIn PDF document text
    • http://patenat.epizy.com/vidonisiwomuruzujeni.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_off0000d974.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD974 5260 bytes
SHA-256: 327202584ce176c2aac81d172feaae23dd032dc24c0940ff2a0be9c93e331c9f
font_01_sfnt_off0000eb30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB30 11936 bytes
SHA-256: 0d073f9535bdffc37d6b133bb92d5755ef501d5f85123631d5a32801ce228dea
font_02_sfnt_off0001134e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1134E 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176

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