Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3af4fa829f1f5d9…

MALICIOUS

PDF

75.7 KB Created: 2021-05-20 02:06:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-22
MD5: e02b9678eb85931a9d1ecf9c1f0b2679 SHA-1: dac6c69081919407a678e2bf1e304b40312c140b SHA-256: b3af4fa829f1f5d9206b5396f53dac39f76c6d9c90b3c65ba686c9b0888a4096
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF document was flagged as malicious by 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 0.9991

Heuristics 5

  • 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://seumenha.ru/strik?utm_term=openstack+installation+on+ubuntu+16.04+step+by+step+pdf PDF link annotation
    • https://nimaxinamupun.weebly.com/uploads/1/3/4/6/134635612/wotudita_makogogij_darimaz.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4370077/normal_5ff8a1669bce3.pdfIn PDF document text
    • https://tonavamajarow.weebly.com/uploads/1/3/4/6/134694337/6208648.pdfIn PDF document text
    • https://jufesuzukexo.weebly.com/uploads/1/3/5/2/135294717/dodezo.pdfIn PDF document text
    • https://nisozamiroxub.weebly.com/uploads/1/3/0/9/130969329/a43b45e4045a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4409607/normal_604bb9ca812d8.pdfIn PDF document text
    • https://xetuvamabur.weebly.com/uploads/1/3/1/4/131409037/3d3734b.pdfIn PDF document text
    • https://munuteme.weebly.com/uploads/1/3/4/8/134862418/resopobixegitil.pdfIn PDF document text
    • https://jofukesor.weebly.com/uploads/1/3/3/9/133999831/840694.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4469836/normal_5fef9c5777a55.pdfIn PDF document text
    • https://febewizonobuwom.weebly.com/uploads/1/3/4/3/134311996/niruw_fudewow_xivufomof.pdfIn PDF document text
    • https://zofawuzi.weebly.com/uploads/1/3/5/3/135323082/579633958672dd6.pdfIn PDF document text
    • https://mamudige.weebly.com/uploads/1/3/0/8/130874639/latiful.pdfIn PDF document text
    • https://nodirodenesubob.weebly.com/uploads/1/3/5/9/135986245/buvipuv-buxupabew.pdfIn PDF document text
    • https://zosufolukariv.weebly.com/uploads/1/3/4/7/134755865/tajoxarasojibu.pdfIn PDF document text
    • https://wasaxedunup.weebly.com/uploads/1/3/1/4/131453111/3968169.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/eb06076f-f9e3-4461-ac68-04867eb43aee/que_es_distribucion_normal.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4d5686a1-cc4b-42a9-b051-9b9d302b81e7/42626499423.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b3292180-c38a-462f-bfa7-dfaae616771b/7708763745.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d8994d86-0512-4ecf-9d33-c4a5946a95e2/whats_a_pecha_kucha.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/78738e45-5dd5-43f8-9f57-eabe14652913/calendario_septiembre_2020_para_imprimir_bonito.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7ebdaaea-6094-43c1-8725-3745860e49eb/aircraft_maintenance_engineer_salary_south_africa.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1d9067fd-4edb-4e91-9ee6-bb4cf5f4cdbf/58649075080.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4a558bd6-0a49-494f-b609-072d8b78b1bd/pewarinunilelawa.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_off0000e60a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE60A 5852 bytes
SHA-256: 322efbdca8dcd666c1c5cf79caece2b674367defb3f490076681e4710f5d8e8d
font_01_sfnt_off0000fa1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA1A 11380 bytes
SHA-256: f7151b722568b67e9ec8a5a0f42d28ba7f9df7b0e8eea96059f49201f04ed50c