Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4598f464cf9165b…

MALICIOUS

PDF

78.5 KB Created: 2021-03-27 12:15:06 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 55fdb85ff85e57a788d247c413d2e822 SHA-1: f80f31eb61d88f1d7709478faf065811290e70c1 SHA-256: a4598f464cf9165b574f63220bd9a269ce4cec7b965055e109cab2b9214dd749
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, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and numerous external URIs are indicative of a malicious document, potentially leveraging embedded JavaScript for redirection.

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://vilenefex.ru/award?keyword=44+phonics+sounds+chart+pdf PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4479451/normal_5fffa25ac75d5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450631/normal_602493ab8eea0.pdfIn PDF document text
    • http://lazategomid.scienceontheweb.net/68188897723.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4467274/normal_5fcb7812565ba.pdfIn PDF document text
    • http://xafopawiki.medianewsonline.com/miworigogi.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://20996a60-9695-4f45-8fdb-44bdc783da55.filesusr.com/ugd/c57cae_d29b14a5a33c439cb5459b3a7820f48c.pdf?index=trueIn PDF document text
    • https://c1f973cf-d719-4acb-8f9e-cd83ae4fb94d.filesusr.com/ugd/057766_52ef6a8a7fbc4d97b370cc10a9a8022b.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/7b0b3304-ba4b-4dfe-98ae-502d80288e16/91666742035.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5509fc76-5800-4eb7-a668-16b11ee34f56/the_lion_the_witch_and_the_wardrobe_gutenberg.pdfIn PDF document text
    • https://591e60e9-54e8-4b06-a9a7-f2e0522969d0.filesusr.com/ugd/1fd4b7_422c879c547842888ccf6123bc3ef5b6.pdf?index=trueIn PDF document text
    • http://titugol.atwebpages.com/20301153171.pdfIn PDF document text
    • https://acfc0e76-311d-46af-9c13-f46c112eb424.filesusr.com/ugd/f90bad_db4faae6bea7415abf7bf30d3e2bcf9e.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/gajakelegeza/1016631388.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d1ac5465-f47c-4289-b6b2-f0aef761f347/to_daddy_from_your_little_girl_poems.pdfIn PDF document text
    • https://6b9ff03a-ef48-417a-a14c-919df0f903d0.filesusr.com/ugd/f459ea_827fd858cbd04a5e92d1e22f52dc5e72.pdf?index=trueIn PDF document text
    • https://f3b8d348-8566-49c9-a9f8-a2c3b9e1bc8e.filesusr.com/ugd/f1c748_3e06e2fa1c314820b6b6824945458358.pdf?index=trueIn PDF document text
    • http://fataragoreb.myartsonline.com/what_are_the_rules_for_naming_covalent_bonds.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/254891c4-db0d-44df-97e3-5346feaab2d4/73675611559.pdfIn PDF document text
    • https://8909b315-4d59-4940-aabf-0fdaa532e0ad.filesusr.com/ugd/4542d9_12ead89420294cecaf1b10a8614576a8.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/kosamupim/avatar_movie_telugu_full.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_off0000edf9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDF9 5204 bytes
SHA-256: c5e5871d2863975ee6325b5f334eecf3730516962d1f7c21cae9d7a28eeaadcc
font_01_sfnt_off0000ffa7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFA7 13084 bytes
SHA-256: 1523f975662e503b5245e506c93d0ed8e0257afbf9ebcd86ec78a24172ce0e8a