Malicious PDF — malware analysis report

Static analysis result for SHA-256 8fa4588a77f9c902…

MALICIOUS

PDF

74.2 KB Created: 2021-03-27 10:10:01 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-22
MD5: 1b5eda7723f2eef33ca555836a9c87e8 SHA-1: 70caaba748d692f58ffaad20085c2ee2c73dfc29 SHA-256: 8fa4588a77f9c902f533495be67c57e0475511392c20452856cd1676d6c058d0
126 Risk Score

Malware Insights

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

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 0.9998

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://zajinet.ru/123?utm_term=apprenticeships+qld+annual+leave+form PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4469349/normal_60036144c2ddb.pdfIn PDF document text
    • http://zufoxemudasoso.iblogger.org/7_continents_and_oceans_map.pdfIn PDF document text
    • http://zemegulobeka.iblogger.org/old_school_pizza_wellesley_menu.pdfIn PDF document text
    • http://lukiduxipapep.mywebcommunity.org/conversaciones_en_ingles_basico_de_3_personas.pdfIn PDF document text
    • http://boforotaje.mywebcommunity.org/how_to_program_honeywell_th4110d1007.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4381997/normal_5fcbb03f12e81.pdfIn PDF document text
    • http://worelimupuvefam.mywebcommunity.org/how_to_do_a_proof_of_service_by_mail.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4486060/normal_604de27dc6289.pdfIn PDF document text
    • http://tafakiduwav.scienceontheweb.net/different_types_of_bolts_and_nuts.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/bewibiwat/sixth_grade_math_worksheets_fractions.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b9af584e-b1e7-4fd4-a450-1745401a456b/1557504122.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0c2bd7fd-d649-4f5b-8409-dab7ee1a3ce4/stone_soup_cafe_ybor.pdfIn PDF document text
    • https://s3.amazonaws.com/wizitifowubux/aix_system_administrator_interview_questions_answers.pdfIn PDF document text
    • http://suwuriru.onlinewebshop.net/biguxaxebojilumul.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d41b11b7-137d-4550-9b7c-ab44892caa85/39784611624.pdfIn PDF document text
    • http://pawepeg.atwebpages.com/lord_of_the_flies_study_guide_answers_chapter_3.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_off0000e5fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5FE 5572 bytes
SHA-256: c4a522a38f9f689cb7c160229cd8901a1ba395f08d140638b2c95918ba94763b
font_01_sfnt_off0000f8ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8CE 10260 bytes
SHA-256: 85bb7bfa1e589f430994c4678cc9235d83cc9219e6294f8caec3e0f2975c1a72