Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1cbcc8a657e6340…

MALICIOUS

PDF

86.4 KB Created: 2021-04-19 05:49:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 28876ec92aef672c8cd9f0a94bdc8e96 SHA-1: 6b169e25e1e09cfc68bcf9a44a9b2beac57d085a SHA-256: b1cbcc8a657e6340a95a80b110d9b55017cd279590902d4400be5a6f7e6740f4
186 Risk Score

Malware Insights

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

This PDF file contains a large number of external links, many pointing to disposable hosting, indicating a link farm or SEO manipulation attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. While no scripts were directly extracted, the PDF structure and embedded URLs are indicative of a malicious document designed to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://pelibifir.ru/strik?utm_term=mental+toughness+training+for+sports+achieving+athletic+excellence PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4367627/normal_603edba9ee30b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368249/normal_602110a2f08fc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365546/normal_6050ca0f0a27c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4422912/normal_604c96bb9261e.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4375207/normal_5fca35dfab3f9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4502268/normal_6032fda87dcdf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379851/normal_603598eff09da.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4404738/normal_60047454e87a8.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4461777/normal_5fdd192ce1ea5.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://jigiwema.epizy.com/91057833683.pdfIn PDF document text
    • http://polexusuzoxofiw.epizy.com/constitutional_convention_1787_word_search_puzzle_answers.pdfIn PDF document text
    • https://21e323bd-7fdd-46e9-a6c7-4880e76d7610.filesusr.com/ugd/0a51c1_def627a5090c48f6bd55e3de29e51659.pdf?index=trueIn PDF document text
    • https://c948e902-2437-43f3-9f1e-7aaad30688a7.filesusr.com/ugd/464a75_16a46ccf709444c0bbca58e3d96a956e.pdf?index=trueIn PDF document text
    • http://josisuvo.epizy.com/school_days_hq_free_pc.pdfIn PDF document text
    • https://e6343aec-df69-40e7-9959-3c0c55bf73c9.filesusr.com/ugd/6a9017_5d5e49ff705f43bfb5b48dd5977ad1c3.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/dubiditiginowo/danatep.pdfIn PDF document text
    • https://c6de0af5-2a4c-46da-924c-839bccb102c6.filesusr.com/ugd/5f1f0f_51637f0842994922a2e6dc52c8775766.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/lebaxa/wimawiverovumugiba.pdfIn PDF document text
    • https://s3.amazonaws.com/taturi/21589632358.pdfIn PDF document text
    • http://vanofixib.epizy.com/how_to_calculate_probability_distribution_function_in_excel.pdfIn PDF document text
    • https://2ddf8be6-044d-4f30-b6fd-16c032829cd6.filesusr.com/ugd/9827ea_6ad425765b1a4443b5f91279bd544663.pdf?index=trueIn PDF document text
    • https://bbf05351-1c49-455c-8ea8-df349977a4d5.filesusr.com/ugd/15c6d6_06e086e34f6c48cbbd3ebbd81aeaa674.pdf?index=trueIn 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_off0001124c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1124C 5408 bytes
SHA-256: 7051432d1f40ff3c4d173627150195b66c9ea79770b6f810cc63c8d21498d2fe
font_01_sfnt_off000124ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124CA 11264 bytes
SHA-256: 313de97ebd41859b8e0faeadd17bf8a55c9b9c367d9b1f84a3ec355527d1f45a