Malicious PDF — malware analysis report

Static analysis result for SHA-256 85651969bc76597e…

MALICIOUS

PDF

71.8 KB Created: 2021-03-05 09:57:26 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 0cf7e32a87fc73cd4bf7c3e2dc44cf24 SHA-1: 2fe47399259a282e58a7bd2cc9b2f2b7eecbb4bc SHA-256: 85651969bc76597e4dc7fb5b4f94c2f421925c4e42028e980d24382b48970e39
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 pointing to disposable hosting, designed to create a link farm for SEO purposes. One prominent URL, 'https://xajibur.ru/strik?utm_term=pn+okeke+physics+textbook+pdf+free+download', is associated with this activity. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution, despite the absence of executable scripts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://xajibur.ru/strik?utm_term=pn+okeke+physics+textbook+pdf+free+download PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4379485/normal_5fdc87ba873c8.pdfIn PDF document text
    • http://jubigale.scienceontheweb.net/17189199298.pdfIn PDF document text
    • http://lezigovedavide.getenjoyment.net/rosaveko.pdfIn PDF document text
    • http://fadulifakibul.medianewsonline.com/79702996056.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4388162/normal_600a797ea02ea.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4376086/normal_5fdb72e46d096.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4414688/normal_5fda7de4133f3.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://ce55c564-0e79-48ac-bd91-a034cff8554b.filesusr.com/ugd/bd1fc0_c6714041419345e2b28c5361c6bd85ff.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/929a919f-96f6-49dc-bd89-75720865b77b/lenovo_t430_laptop.pdfIn PDF document text
    • https://c140f178-ee45-427e-91fe-a3c5f821f67e.filesusr.com/ugd/ebc5f9_0596754a09c048f9a7f9966e58997c89.pdf?index=trueIn PDF document text
    • https://b2d1eea7-aef5-47fc-962c-88b5513ecafc.filesusr.com/ugd/3a57bc_b54f78dea2704d31a7248792b8fc6525.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/c77d3633-2d6f-4f0f-a11e-c7b25151a55d/fovagefi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ed89608a-0709-4a31-9211-70c884a481dd/insinkerator_evolution_compact_parts.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/213a45b0-347b-4eac-9c73-e0dd5f1c03a7/9186354503.pdfIn PDF document text
    • https://18cb0a1d-3822-48a5-9ca0-56465202bc9b.filesusr.com/ugd/96564c_d13425fa3a064827b4a5b1ba1df4e394.pdf?index=trueIn PDF document text
    • http://xolavozezimodan.onlinewebshop.net/65755061384.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2d1f5663-4b59-4671-8090-1fa5060d89cc/93003731590.pdfIn PDF document text
    • https://77a80da1-97a3-4b40-ba11-54c6d232eb66.filesusr.com/ugd/39a0fd_3b512e166ce844e6a5e3bfb0739ca536.pdf?index=trueIn PDF document text
    • http://vipuzala.myartsonline.com/luruk.pdfIn PDF document text
    • https://9de673a2-3b8e-40eb-bbf5-c0ad8e71a3da.filesusr.com/ugd/bd5c68_2fffa5c1a9dd4fcaae9376461387486f.pdf?index=trueIn PDF document text
    • https://146c8b6c-0b46-450b-8ed0-b45f1e2a4974.filesusr.com/ugd/b58d21_11df98285dc549edb06b60337d721f62.pdf?index=trueIn PDF document text
    • https://7e6b698e-d56f-4a21-8c48-787e2f6d39f4.filesusr.com/ugd/7836c9_9e8c170897b84bf784e159146220a503.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/e161ef27-7ae7-48f1-a768-f56f0286ff6a/marlin_336cs_specs.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6c5b041d-0ed6-4e22-8802-a59505e1dc1a/asus_rt-n10e_wireless_n_router_configuration.pdfIn PDF document text
    • https://8ed62699-7d02-4439-b935-4286882ef7d4.filesusr.com/ugd/229b11_f16499d1c8734b6390dc709fd13b1eed.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/829bcba3-b621-4e39-bb9d-8e787abdbf40/what_hunting_season_is_it_in_vt.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_off0000d9f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9F2 5712 bytes
SHA-256: 92f7bfbcbdc7e4cded52e2d945de5161dc566937cf959709eee87d4e7ddcb162
font_01_sfnt_off0000ed7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED7A 10544 bytes
SHA-256: da918ab1c8b1769870db93ab4785085d94ae12a2b9c5a906f3eb12f72acdb19c