Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c78fbd5daf81499…

MALICIOUS

PDF

81.2 KB Created: 2021-03-12 12:56:46 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-17
MD5: 035ce4d3f74be1f1e577e695612331ff SHA-1: 9bad6a0a37e964fe3553810c2017636111793028 SHA-256: 4c78fbd5daf8149954d0e141b41b113b36fadec876ff59725cf06e0dcb364561
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many pointing to disposable hosting services, suggesting a link farm or SEO manipulation tactic. The primary URL, https://jacksth.ru/award?keyword=amplifier+repair+book+pdf, is presented as a lure for a book download. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution through the linked content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://jacksth.ru/award?keyword=amplifier+repair+book+pdf PDF link annotation
    • https://vinovubetiloj.weebly.com/uploads/1/3/4/6/134679092/9239367.pdfIn PDF document text
    • https://nuranisemamev.weebly.com/uploads/1/3/5/3/135324344/1662242.pdfIn PDF document text
    • https://ranaxeli.weebly.com/uploads/1/3/4/4/134478161/sebevobe.pdfIn PDF document text
    • https://vubufogos.weebly.com/uploads/1/3/4/7/134766152/rozararopuros.pdfIn PDF document text
    • https://famotufenimuz.weebly.com/uploads/1/3/4/1/134132127/1974543a1.pdfIn PDF document text
    • https://cdn.sqhk.co/xaxovowupofa/VI8RMjq/12216687077.pdfIn PDF document text
    • https://weduparazibad.weebly.com/uploads/1/3/4/7/134710999/xitelugizif.pdfIn PDF document text
    • https://cdn.sqhk.co/pirasemofoge/Whbggj7/22940215310.pdfIn PDF document text
    • https://vakupakofusiwu.weebly.com/uploads/1/3/5/3/135399484/bigej.pdfIn PDF document text
    • https://sazadasixitabe.weebly.com/uploads/1/3/4/4/134404720/257916.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/0e6cf5df-cf1a-4bab-80e0-2f2ace1f280a/68033470375.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d97687ba-e933-41d1-936d-a2ded4a0c7d6/how_to_light_a_kerosene_heater_manually.pdfIn PDF document text
    • http://zubeleboju.epizy.com/jipajatijobasatix.pdfIn PDF document text
    • http://gopikobupi.epizy.com/english_guide_book_for_class_8.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5e5ca40b-5c8b-47b9-9161-a8a4779b9b3f/kofipoxogibure.pdfIn PDF document text
    • http://kikukuvikato.myartsonline.com/61555228657.pdfIn PDF document text
    • http://tudugir.atwebpages.com/pdf_annotator_7._0._0._702_crack.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b6a78a82-2974-4c37-a920-9b46cbdea146/titufotor.pdfIn PDF document text
    • http://vilepobafomunow.atwebpages.com/what_is_the_cheapest_young_living_oil.pdfIn PDF document text
    • http://kedisijusa.onlinewebshop.net/download_samsung_xpress_m2880fw_printer.pdfIn PDF document text
    • http://mulozeraxepe.epizy.com/58394854777.pdfIn PDF document text
    • http://kewugozosefo.epizy.com/85112234385.pdfIn PDF document text
    • http://xikisefux.epizy.com/how_much_to_rebuild_a_302_motorcycle.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_off000100de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100DE 5200 bytes
SHA-256: 6bae3fcd4e7aceae013d4e66ca2c521cbb9d163dc0ea1dafde2bf95b4c5b5705
font_01_sfnt_off00011273.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11273 10828 bytes
SHA-256: 73db7d921673a4bdd9b171135fe1f1adcea79d1e95a74b318d4da68b03dcea5c