Malicious PDF — malware analysis report

Static analysis result for SHA-256 c3993b0e370c0a8b…

MALICIOUS

PDF

38.4 KB Created: 2020-10-08 21:14:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: d8680de2e27dc1cc506a7085f66aa610 SHA-1: ee435fadb9236fcd5304e8914385ec2bf438ca54 SHA-256: c3993b0e370c0a8b8fffc117a9401f56bbfb7a5c94fd87188228ea74ff0fdf4c
124 Risk Score

Malware Insights

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

The PDF document contains numerous embedded links, with one specifically identified as a malicious redirector. The heuristic 'PDF_MALICIOUS_REDIRECTOR_LINK' indicates that the URL https://cctraff.ru/strik?keyword=elementary+linear+algebra+howard+ant leads to known malicious infrastructure. The document body, though heavily obfuscated, also contains this URL, suggesting an attempt to lure users to a malicious site under the guise of academic content. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://cctraff.ru/strik?keyword=elementary+linear+algebra+howard+ant In PDF document text
    • http://files.leppingnation.com/uploads/1/3/2/7/132712435/faxikojoravuk_morozam.pdfIn PDF document text
    • http://tufufobaj.visionquest50.com/uploads/1/3/1/4/131452903/beruzimiwefuju.pdfIn PDF document text
    • http://files.masterpiecestudiosnc.com/uploads/1/3/0/8/130874113/e8ef68.pdfIn PDF document text
    • http://files.thinkgrafix.net/uploads/1/3/2/6/132681436/rijisosu.pdfIn PDF document text
    • http://butotori.embcmanning.org/uploads/1/3/0/8/130873830/todagefelesu-nulasaguxox.pdfIn PDF document text
    • http://files.larrylilly.net/uploads/1/3/2/6/132681694/keripi.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://cdn.shopify.com/s/files/1/0440/5769/0277/files/sominiwudezutiditasepila.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0482/5717/1618/files/60974104377.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0435/8553/6159/files/professor_layton_vs._phoenix_wright_ace_attorney_3ds.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/dc6be31a-1395-4861-957c-d8fcab23da8c/sifijetizofet.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/110b81f0-78e6-4600-b92c-b0dae5479b6e/82879090297.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cd773a89-9da3-4767-83fb-584e470822de/dunerimebesiximijilobas.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/570b871c-af40-42c2-ba52-c6950eae9dfe/20863317473.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/60b191d8-bf4a-48a7-af0d-61919c3a189a/wagolujaxopugokefubarido.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_off00004e14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x4E14 5352 bytes
SHA-256: 7809268a18796a49e33ab0209c7f14ebf1b28a34eb8aa58c0058f252d4b3605b
font_01_sfnt_off0000602f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x602F 14472 bytes
SHA-256: dba415fa75c0fd1b65efa650eff65f31e1076e7e81db897f3bd18d9ca1a4223c

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