Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f8cbc24cf1a91bd…

MALICIOUS

PDF

75.8 KB Created: 2021-03-29 23:43:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: 574e31197235fbb26c681886ec6f44ae SHA-1: 54a12e5ca842732870e52b1184a68782f4e0530c SHA-256: 4f8cbc24cf1a91bd988e988f8490d1079e193a6187ea6e3ab895149f043b1faa
186 Risk Score

Malware Insights

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

This PDF file is identified as malicious by multiple heuristics and an ML classifier, indicating a phishing or trojan distribution attempt. It contains a large number of external links, many pointing to disposable hosting, suggesting a link farm designed to redirect users to malicious content. The primary external URL, https://golowaki.ru/award?keyword=conjunctions+exercises+with+answers+pdf, is likely part of this scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://golowaki.ru/award?keyword=conjunctions+exercises+with+answers+pdf PDF link annotation
    • https://cdn.sqhk.co/muwunupudi/eS59heP/need_for_speed_rivals_cars_wiki.pdfIn PDF document text
    • http://modozadubop.mywebcommunity.org/athens_transit_map.pdfIn PDF document text
    • http://fefiwizam.sportsontheweb.net/38901262869.pdfIn PDF document text
    • https://nuguserofaj.weebly.com/uploads/1/3/0/9/130969707/pugejokatomabuwufego.pdfIn PDF document text
    • https://dilomosef.weebly.com/uploads/1/3/4/3/134316650/3584500.pdfIn PDF document text
    • https://babanude.weebly.com/uploads/1/3/4/0/134017813/979623.pdfIn PDF document text
    • https://cdn.sqhk.co/zonakagud/hNXsjcq/paleolithic_technology_and_human_evolution.pdfIn PDF document text
    • https://cdn.sqhk.co/riragimi/hjjSaSh/38779302977.pdfIn PDF document text
    • https://jiresuzava.weebly.com/uploads/1/3/4/7/134706808/mejobe.pdfIn PDF document text
    • http://jepisafidezegun.scienceontheweb.net/xekon.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://68f06c25-eb64-4e0a-94e3-a0e33e610147.filesusr.com/ugd/463ace_55304ec4ae4a48fdbd79dd9490a4ad5a.pdf?index=trueIn PDF document text
    • https://6f847715-c85a-45d9-ae5c-7c68cc800588.filesusr.com/ugd/6e100b_9be9c6a480834bab92c011a96b5a914d.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/9f9858c9-6966-4de0-99ff-5b6ea3127138/sunbeam_sm0701a7e_microwave_oven_manual.pdfIn PDF document text
    • https://52c77544-2eb8-427c-ad0e-a8a7e2ea9366.filesusr.com/ugd/93288f_105867aa89984e8cb6f25ba80b2fd492.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/lekezaru/7485394159.pdfIn PDF document text
    • https://s3.amazonaws.com/wiwuxot/enfermedades_del_sistema_endocrino.pdfIn PDF document text
    • http://gavawekib.myartsonline.com/reduce_file_size_mac_preview.pdfIn PDF document text
    • https://s3.amazonaws.com/falevi/dark_web_app_for_pc.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/24def4d0-c77f-46de-b6e1-a90bdd77bd62/52846409676.pdfIn PDF document text
    • https://abbf68a8-5b21-4996-91be-11266bd273ed.filesusr.com/ugd/9374a7_6f2c5445bd294104ab5a5e5556553fd5.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/24367325-7b56-42cb-86b2-354b6381526e/lexaja.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_off0000ec03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC03 5352 bytes
SHA-256: a5771b62e28f5fa8824fca57fd4f6416bb5531fdc6ae359d63942c42d3c322c9
font_01_sfnt_off0000fe4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE4D 10384 bytes
SHA-256: 78789470eb493538b22f07351b93dc2eb990c74b6eaecf0e0d9850e79fe15b5a