Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9ea58f60df045e4…

MALICIOUS

PDF

85.9 KB Created: 2021-05-08 00:41:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 909436a5ba16c159fe0710eff096bce6 SHA-1: 272d4a51348ef2087c2d056633b60556f45bba39 SHA-256: a9ea58f60df045e4a483f4237e0a1904bcb2d903997b16a16d1a89cc57a333db
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, indicating a link farm or phishing attempt. The ClamAV detection and ML classifier strongly suggest malicious intent, likely to redirect users to malicious sites for credential harvesting or further malware delivery. No scripts were extracted, but the PDF structure itself is used to facilitate the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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 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://lozipotod.ru/strik?utm_term=5th+grade+prefixes+suffixes+and+roots+worksheets PDF link annotation
    • http://xepidenad.scienceontheweb.net/94970044827.pdfIn PDF document text
    • https://lefojokux.weebly.com/uploads/1/3/5/3/135399193/towuko-serarufilo.pdfIn PDF document text
    • http://figimumagoko.mygamesonline.org/how_to_clean_samsung_washer_filter_top_loader.pdfIn PDF document text
    • https://vakogupomuniv.weebly.com/uploads/1/3/4/6/134610568/dexosirurag.pdfIn PDF document text
    • https://kefuvarunif.weebly.com/uploads/1/3/0/7/130739830/7049037.pdfIn PDF document text
    • http://gekifek.scienceontheweb.net/27548232988.pdfIn PDF document text
    • https://lexedixejorew.weebly.com/uploads/1/3/1/4/131438453/sakudeke.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://relivoziz.atwebpages.com/sinha_s_comprehensive_anxiety_test.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7051b093-6871-4a1b-a81c-ee4557e6439d/marvel_what_if_series_episode_1.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/81fdef44-eb5e-4410-b486-6b1726ec1b7b/lg_tromm_washer_error_code_te.pdfIn PDF document text
    • http://vuzuwukef.atwebpages.com/93123526692.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d91a747e-6b4f-4d62-99cc-da5a7123d0ae/how_big_is_a_6_quart_pressure_cooker.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fa2f12b4-b87a-4f09-bbaf-c1ff96d87f1e/how_to_change_voicemail_on_vtech_digital_answering_system.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7658c6c9-78ef-4204-96c0-cea7636bb318/will_there_be_a_sequel_to_dantes_inferno_game.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7d86729d-d8f5-43aa-aceb-958af13a6562/15886910125.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0595f106-b488-41fa-81d8-67b0ce41b4cb/33988887101.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/65e62fcf-7182-4a8e-ae13-a50ceaebe853/dewalt_d51844_rebuild_kit.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/85926d16-1dda-4c39-95ca-d46d6d37afba/english_learning_course_online_in_hindi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0b19dfcd-8234-4aad-b878-5eec7399ef9f/3461754650.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/516b8195-de74-42df-8494-854c1156413b/40939076021.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_off00011077.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11077 5524 bytes
SHA-256: 3d33ca18be264b5574514ed11436adf980439c8d5be52e7823655bea0078a18f
font_01_sfnt_off0001235f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1235F 11428 bytes
SHA-256: 028b7015d402dc037b53b9281511ea2b773ec3750e1c1e335bbb1f0290b97432