Malicious PDF — malware analysis report

Static analysis result for SHA-256 861c7cd83720ee65…

MALICIOUS

PDF

73.7 KB Created: 2021-06-02 16:00:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: 2cddfcdba9c9f75114a430896caafdbf SHA-1: 97de2414b613392a938a99a503e6347fa99a239b SHA-256: 861c7cd83720ee6569d574133a3932861e80d0ece9bcfe1a9cbe6eed933450d1
186 Risk Score

Malware Insights

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

This PDF file functions as a link farm, presenting itself as a search result for a free PDF download. It contains numerous external links to other PDF files hosted on disposable domains, likely to improve search engine rankings for the initial lure. The ML classifier and ClamAV detection strongly indicate malicious intent, classifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://oniceh.ru/pbw?utm_term=intermediate+accounting+6th+edition+pdf+free+download PDF link annotation
    • https://kurixaxewa.weebly.com/uploads/1/3/1/3/131383664/mufup-sufuvufegodefum.pdfIn PDF document text
    • https://wikabolodaj.weebly.com/uploads/1/3/4/6/134648749/zovesasadunipi_dorizivukatatis_kimudevupekiz_ribexabu.pdfIn PDF document text
    • https://farisogu.weebly.com/uploads/1/3/4/3/134307724/3237817.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4374207/normal_5fdffdf8c713b.pdfIn PDF document text
    • https://ditezuni.weebly.com/uploads/1/3/5/3/135350757/1391801.pdfIn PDF document text
    • https://tamoniwezetiro.weebly.com/uploads/1/3/5/9/135961995/vuledejuropalipadagu.pdfIn PDF document text
    • https://xegoguvaposa.weebly.com/uploads/1/3/4/6/134677344/2e02c9a3316d9.pdfIn PDF document text
    • https://jojipizi.weebly.com/uploads/1/3/1/6/131606457/4343773.pdfIn PDF document text
    • https://nogusuxewi.weebly.com/uploads/1/3/1/4/131438155/mafekujudozoso_rukijedajigi_jiduxeli.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4419193/normal_605d802eea706.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4384154/normal_5fe17c24c4486.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4408352/normal_5fd097783c28c.pdfIn PDF document text
    • https://mozijazese.weebly.com/uploads/1/3/4/4/134460989/sunerijexoz.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454054/normal_601de28d8a153.pdfIn PDF document text
    • https://dozumudokasalog.weebly.com/uploads/1/3/4/9/134902229/wekozugop.pdfIn PDF document text
    • https://xobojurum.weebly.com/uploads/1/3/4/5/134599739/viwev.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426260/normal_602f4f8d9ea16.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/4b0eb2c4-8ca9-48cc-b3cc-73cdd4946854/58592077635.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b827ebb2-4add-4d22-98cc-2191f00b5ce6/nail_salon_open_sunday_charlotte_nc.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b17e5745-c786-4224-b32a-fc148c6d1600/why_students_should_wear_uniforms_persuasive_essay.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_off0000e0dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0DC 5576 bytes
SHA-256: 4858d0807069f6f65e738b0cbaec73917ceb740ad8d613492967eadf446f0cb3
font_01_sfnt_off0000f3b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3B8 11112 bytes
SHA-256: 5807630de89402069b36517d85dec484425651098d5f118f937864afdd69ddfc