Malicious PDF — malware analysis report

Static analysis result for SHA-256 831101b7f0cb8924…

MALICIOUS

PDF

76.9 KB Created: 2021-03-19 14:28:06 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: cca09da2d864ef2c34d71ccc288d9c86 SHA-1: a110b2624fb583640fd42abc1342f1fde7e1cf6c SHA-256: 831101b7f0cb892481386c4f5ba6dc30949062b007f29496514c1946177c195c
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 domains, suggesting a link farm or SEO spam operation. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and heuristic firings point towards the exploitation of PDF vulnerabilities or social engineering to redirect users to malicious sites.

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://botokaw.ru/wix?keyword=spanish+2+study+guide+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4483873/normal_6040fca0d7c8c.pdfIn PDF document text
    • https://lamuwopinu.weebly.com/uploads/1/3/4/6/134632291/guzofatejib.pdfIn PDF document text
    • https://kavavori.weebly.com/uploads/1/3/4/0/134012315/tawipaf.pdfIn PDF document text
    • https://labelamujevodit.weebly.com/uploads/1/3/1/6/131606697/3295378.pdfIn PDF document text
    • https://nukoxifade.weebly.com/uploads/1/3/4/3/134332817/gazesarizot.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4407066/normal_604821aecc92e.pdfIn PDF document text
    • https://pavemizex.weebly.com/uploads/1/3/1/6/131606984/fodowi-ximezokeve-faranesotot-purubutopuro.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4458148/normal_601c672d6b473.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4414494/normal_60541e7a45fad.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4465131/normal_60008688c5120.pdfIn PDF document text
    • http://zokazurimila.mygamesonline.org/atoms_and_the_periodic_table_coloring_puzzle_worksheet_answers.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4464739/normal_5fc7f9e7a9f70.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4380522/normal_601e0c92361b6.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/mixanaz/86080270299.pdfIn PDF document text
    • http://bugazepoja.onlinewebshop.net/72064127067.pdfIn PDF document text
    • https://9cf5cc10-3c2e-4e30-ae6b-73ed7beed88a.filesusr.com/ugd/5c2b46_ee654009fb394212951325baba76dd50.pdf?index=trueIn PDF document text
    • https://fe2b84af-b373-48e0-a714-f820169e3fe9.filesusr.com/ugd/ed1d2e_6a3558107193417287692f9f7049b33d.pdf?index=trueIn PDF document text
    • https://78905da9-dd21-4190-abaa-c894c042e703.filesusr.com/ugd/851c7c_3d658d150ec34db98ae4f6d1e3ec0281.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/mejigavukolu/cot_bed_sheets_70_x_140cm_argos.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_off0000eb60.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB60 5512 bytes
SHA-256: 9622139a0e5eb5ce44f97db6aecc641f11461f58a7614feb15ef676c14950cc7
font_01_sfnt_off0000fe2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE2F 11932 bytes
SHA-256: 059dc0f382d5514df6e73a29122082877892efa92dbf457648cf94c460e2575f