Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f345d9e599c43a4…

MALICIOUS

PDF

73.9 KB Created: 2021-03-24 13:11:19 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: c8b89b7d84febf15b7401134f84b7f4d SHA-1: 0398027b80e62addaa4e95c23dc0563e742eb3c5 SHA-256: 5f345d9e599c43a43000c59cf356322b7287359bf635542a860af67f94c38269
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

This PDF was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. It contains numerous external URIs and is part of a link farm hosted on disposable domains, suggesting a phishing or SEO poisoning campaign. The primary external URI observed is https://zajinet.ru/wix?keyword=vertex+focus+and+directrix+worksheet.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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/wix?keyword=vertex+focus+and+directrix+worksheet PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4443594/normal_5fed7b9d30fcb.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4487665/normal_5fda085413604.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4376849/normal_60009125dbc4a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4486523/normal_6035fe1e64c5f.pdfIn PDF document text
    • http://xoxosedefoxadu.mygamesonline.org/qu_significa_la_palabra_destruir_en_la_biblia.pdfIn PDF document text
    • https://cdn.sqhk.co/fewisezux/hihagew/66683773258.pdfIn PDF document text
    • http://bogipeborowe.sportsontheweb.net/subway_map_new_york_city.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4402032/normal_6017f69d6a99f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4392873/normal_604d3bb7aabbb.pdfIn PDF document text
    • https://cdn.sqhk.co/sunomedude/jagjmPv/zatolexunevutevar.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4464709/normal_5ff2cdd631e35.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366009/normal_603b6b2d7887e.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4467589/normal_5fdcfb5fee81a.pdfIn PDF document text
    • https://cdn.sqhk.co/feluxolid/sFEjdfR/ritefupazagoxuvozugife.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4473902/normal_60420e31688c7.pdfIn PDF document text
    • https://cdn.sqhk.co/muwunupudi/fgiPgcR/desert_island_survival_game_items.pdfIn PDF document text
    • http://dumubemajizukov.medianewsonline.com/artificial_neural_network_definition.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://fufuzadawefor.onlinewebshop.net/definition_of_community_policing.pdfIn PDF document text
    • https://s3.amazonaws.com/xelimewat/79677858248.pdfIn PDF document text
    • https://s3.amazonaws.com/xisefowu/88648801956.pdfIn PDF document text
    • https://74bb8966-1fc2-43cb-a641-24c20f380d28.filesusr.com/ugd/84c7b5_0e2b6c57a7464e5e9676475eed8717cd.pdf?index=trueIn PDF document text
    • https://3c3b6f52-20a2-448a-be11-eec5930c502f.filesusr.com/ugd/0ca786_0ac2ec3a7be74bff809970b8b4c6454b.pdf?index=trueIn PDF document text
    • http://sofibimibojas.myartsonline.com/56265180505.pdfIn PDF document text
    • https://s3.amazonaws.com/pujirageg/full_hd_movies_kabir_singh.pdfIn PDF document text
    • https://s3.amazonaws.com/dobikasukavu/64787732491.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_off0000e1fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1FB 5268 bytes
SHA-256: 93036a90a2c69969334acec5c5f7805176f215aa2e17d857d9ab583e41af046a
font_01_sfnt_off0000f401.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF401 11084 bytes
SHA-256: d5f24076c7b50fa8de6560cdfaec4fad61d78245f74af9691c012e6ae896c554